Hole size

[kckinwa]

I may be able to pick up a brand new 75 gal glass aquarium with built in overflow and stand for less than 300.00, again all brand new. Not a bad price so my question is this. I am sure the pre-drilled overflow holes are the standard 1" in diameter. I would like to know if it is possible to increase the size of the hole to 1 1/2" (if room allows)? I am sure this is tempered glass as it is the bottom of the tank. If there is no way to enlarge the holes then the only way to achieve over 750 gph would be a external hang on back overflow.

[sleepydoc]

If it is tempered then there is absolutely no way to increase the size of the hole. Are the holes 1" or are they made for a 1" bulkhead?

If it is the standard corner overflow, I would run a Herbie and have the return come over the back. If the back is not tempered, you may be able to drill the back for the return.

[kckinwa]

Yes it is drilled for a 1" bulkhead, and after many hours of research, 1 inch is in all cases for tanks above 15 gallons not enough flow for a quality reef. So back to the drawing board. Unfortunately I think the only way to get a 1 1/2" is to go custom made.

[ca1ore]

Yes it is drilled for a 1" bulkhead, and after many hours of research, 1 inch is in all cases for tanks above 15 gallons not enough flow for a quality reef.

I think your research may be flawed :)

Assuming your proposed purchase is a standard 75, the overflow will have a pair of 1 3/4 holes at the bottom intended for 1" bulkheads. Do as sleepydoc suggests, and set it up as a herbie-style drain. Not sure how much through sump flow you think you need, but dual 1" pipes will be more than sufficient for a 75. You should be thinking power heads for most of your in tank flow requirements.

[woodnaquanut]

I think your research may be flawed :)


+1

I have a 120G using 1" bulkheads. Lots of tank turnover. Internal powerheads for flow.

[kckinwa]

From days of research it appears that the suggested turnover from sump to dt should be at least 10 times the dt volume so essentially 750 gph, this was also the recommended flow rate suggested by several lfs for a healthy, vibrant reef tank. And gravity fed a 1 inch pipe drain rate is roughly 350 gph. Now sure you can go full siphon ie. Herbie overflow and achieve up to 950 gph, though this method is inconsistent, and impossible to keep stable long term with oto or manually topped off methods. Not to mention redundancy is the best prevention of wet carpet. Considering my 75 gallon clean up in my living room last week, I am looking for assurances. Here is a extensive study performed on bulkhead sizes. http://www.wetwebmedia.com/BulkheadFloRateArt.htm
please keep the feedback coming I appreciate all the help.

[ca1ore]

If your days of research had included RC I think you will find that most experienced reef keepers run 3-5 times tank volume through the sump per hour. In fact, I actually run even less than that. As I said in my earlier response, better to provide in tank flow with power heads.

Not really getting your comments on the herbie; you appear to be contradicting yourself. Herbie is dead easy to implement, and provides important redundancy - as well as being silent.

[Wryknow]

2 x 1" drains are plenty for a 75 gallon. That's what I have on mine with Tunze 1073 return (I've also run it with an E-heim 1262.) I'm running Durso overflows and it''s very quiet with the right modifications. I did do a test and if one drain gets 100% clogged and verified that the other drain can handle the full return, but it does do the siphon/drain/fill/siphon cycle. Certainly acceptable in an emergency situation though as the noise is a pretty obvious sign that there's an issue and it keeps all of the water in the tank.

[kckinwa]

Lol I did actually research here at RC http://reefcentral.com/forums/showthread.php?t=2094775 And it appears to be a split decision in here as well. However I am not talking to in tank flow, this I am aware needs to very based on livestock in tank. I am however talking about turnover rate from tank to sump, and as I said even 4 out of 4 of the local fish stores (marine not fresh and definitely not big box stores) said the same thing, the more you can turn over your water from the dt to the sump/skimmer the better as you are clearing the living environment from bacteria, algae and detritus. In return for this your corals grow faster and more vibrant. Now that being said I do realize that a lfs job is to sell product, so yes it is in the stores best interest to recommend higher flow. And if all this information is snake oil to sell more product then shame on me for not listening to fellow reefers, but as I said even RC peeps seem to be split on this particular topic and with all the info gathered from all sources, it appears to be about 70 percent recommending higher is better with the magic number landing in the 7-10 times range. And I do understand that it makes no sense to send 750 gph through my sump if my skimmer can only handle 300 gph, which is why I have yet to purchase my skimmer, I first need to resolve my ignorance to turnover. Now as to the Herbie issue, I am still researching this and as I was trying to say without detail earlier is that there is several variables at play from my understanding to get a herbie to work correctly and I can not test those variables without the tank on hand. So with that being said my concern is can i get it silent without overflowing my sump. From my understanding you need your main line to be roughly 6 inches lower than your emergency line in the overflow to work properly and without the tank here I can not calculate the amount of water with power failure that would end up in the sump. Like I said, I am afraid of another flood in the living room, so I am not trying to be a pain in the rear, I am just trying to be extra cautious on my next attempt. Thanks again to all the help on these issues though I thank I may have drifted a bit out of the DIY arena.

[Gorgok]

I have a DC12000 in my 40B sump on my 75... Probably running at about half its capacity (controller and head), which is somewhere in the area of 1000gph. I don't see any reason to slow it down.

If your skimmer was actually the means water goes from the drain section to the return section i could see a reason to try and match its processing rate, otherwise its gonna do what it does in its own time, either in nearly standing water or 'rushing' water...

[sleepydoc]

Remember - just because the bulkhead is 1" doesn't mean the rest of the plumbing needs to be 1". You can (and in most cases should) upsize the plumbing to at least 1.25".

I have a 120 'reef ready' with a corner overflow Herbie, 1.25" pipes through the 1" bulkhead. I estimate I'm running about 5-600 gph through my sump, and I still have the main drain throttled back significantly.

In regards to the sump flow vs skimmer capacity, you don't need to worry about matching those exactly. Even if you do, the skimmer will end up 're-processing' a significant portion of the water anyway. It's not like a filter where you can flow all the water through it.

The Herbie is not that complicated. I posted a quick summary of it here (http://reefcentral.com/forums/showpost.php?p=23260833&postcount=1735). As people have said earlier, it's a great option for situations like yours. If you're really concerned about a failsafe system, you can drill the back and convert it into a Beananimal (http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx).

You can also get a rough idea how much water will drain back to your sump - std 75 gallon is 48 x 18 = approx 3.7 gallons per inch of depth. (48*18/231 cubic inches per gallon) If your return pump outlet is 2" below the surface, you will drain about 8 gallons of water into the sump.

There are many successful reefers who have done exactly what you are worried about doing; I think you're over-thinking the problem!

[kckinwa]

Lol yes I am over thinking this, only because many refers have successfully had acrylic dt's and my fist attempt at acrylic, my confidence, all 75 gallons of it ended up in my carpet, pad and subfloor, ha ha, I can laugh about it now but I am extremely leary. So needless to say my return to the hobby has been expensive and have not bought any live rock, fish or corals yet, lol nor do I even have a tank now. So I am just being cautious cause clearly I'm stuck in a streek of bad luck right now. Thank you for the herbie info, I think I got that part of my build squared away. I now need to decide if I will buy the glass tank or have a local professional build me exactly what I want from acrylic. I was thinking that if I have one built I would have the entire back side of the tank a toothless coast to coast overflow about 4 inches by the width and depth of the tank, this way I can run all drain and returns hidden behind the black back wall. Essentially if you look through the tank all you see is a black back wall with 1 return nozzle in the middle. The top of the overflow would have a hinged black acrylic lid that when closed it leaves a gap roughly 1/8 of an inch or just enough space for water to cascade into the box. (hinged for accessing the box for maintenance) and two small pumps, one in each corner to keep debris and detritus suspeded in the overflow so it can make it to the sump without being trapped in the box. What do you think?

[Wryknow]

You're definitely over-thinking this. The drain/overflow calculator on the home page of this website is tried and true. More is not always better. At a certain point you're just spending a lot of money on moving a lot of water up and down from your tank to your sump. Trust us! This is my 5th saltwater tank. 5 times tank volume per hour is really more than adequate for a return flow. 2 x 1" drains really can handle that volume very easily and quietly with a number of different design options (Herbie, Bean Animal, or Durso!) You definitely want more water movement than just the return at 5 x volume, but you'll want to accomplish that through powerheads or a closed loop system.

[sleepydoc]

A lot depends on whether you get glass, acrylic, custom built or off the shelf, etc. You initially said you were getting a 75 gallon pre-drilled glass, which typically means 2 holes in one corner of the bottom.

if you are building yourself, I would get a coast to coast with holes drilled for a Beananimal overflow. Like I said before, a Herbie is a great option if you have a 2-hole corner flow tank, but a Beananimal is by design easier to keep adjusted and more fail-safe.

The cheapest option would be for you to get a standard 75 gallon, drill it and install the overflow weir yourself.

[ca1ore]

Lol I did actually research here at RC http://reefcentral.com/forums/showthread.php?t=2094775 And it appears to be a split decision in here as well. However I am not talking to in tank flow, this I am aware needs to very based on livestock in tank. I am however talking about turnover rate from tank to sump, and as I said even 4 out of 4 of the local fish stores (marine not fresh and definitely not big box stores) said the same thing, the more you can turn over your water from the dt to the sump/skimmer the better as you are clearing the living environment from bacteria, algae and detritus. In return for this your corals grow faster and more vibrant. Now that being said I do realize that a lfs job is to sell product, so yes it is in the stores best interest to recommend higher flow. And if all this information is snake oil to sell more product then shame on me for not listening to fellow reefers, but as I said even RC peeps seem to be split on this particular topic and with all the info gathered from all sources, it appears to be about 70 percent recommending higher is better with the magic number landing in the 7-10 times range. And I do understand that it makes no sense to send 750 gph through my sump if my skimmer can only handle 300 gph, which is why I have yet to purchase my skimmer, I first need to resolve my ignorance to turnover. Now as to the Herbie issue, I am still researching this and as I was trying to say without detail earlier is that there is several variables at play from my understanding to get a herbie to work correctly and I can not test those variables without the tank on hand. So with that being said my concern is can i get it silent without overflowing my sump. From my understanding you need your main line to be roughly 6 inches lower than your emergency line in the overflow to work properly and without the tank here I can not calculate the amount of water with power failure that would end up in the sump. Like I said, I am afraid of another flood in the living room, so I am not trying to be a pain in the rear, I am just trying to be extra cautious on my next attempt. Thanks again to all the help on these issues though I thank I may have drifted a bit out of the DIY arena.

I applaud you for taking the time to think this through ahead of time. Frankly there are many people who do lots of things without really thinking about why they do it. That 70% advocate higher flow through the sump does not mean that it is the right, or necessary, thing to do (average tenure in the hobby for RC members even is probably just a few years - listen to the ones who have been at it for a while). The only things that flow through the sump MUST accomplish are to adequately skim the display tank surface and ensure even heating. Both of these can be accomplished with 3-5 times tank turnover. Any more than that is simply heresay IME. Also, there is no relationship, nor correlation, between flow through the sump and skimmer pump capacity. One simply has no bearing on the other. If someone tells you there is, ask them to explain why and decide for yourself whether said explanation makes sense at all.

[uncleof6]

I applaud you for taking the time to think this through ahead of time. Frankly there are many people who do lots of things without really thinking about why they do it.

The number of people who do lots of things without really thinking about it, may be lower than one would imagine. That said, by far the larger number of those doing "anything" have very little understanding of how things actually work; the "why they do it" is very obvious: because they were told that is the way to do it. They were told to do it that way, by someone else with little understanding of how things actually work, who was also told to do it that way by... the very basic definition of hearsay.

That 70% advocate higher flow through the sump does not mean that it is the right, or necessary, thing to do (average tenure in the hobby for RC members even is probably just a few years - listen to the ones who have been at it for a while).Following this line of thinking, the 70% (actually it is much higher) that believe that the "skimmer" provides gas exchange for the system, are actually very wrong, and the minority that knows that it does not, are actually right. However, that is not how it is viewed. Those speaking against the absurd notion of "gas exchange" in the skimmer (C0₂ crosses the air water interface easily due to high solubility, O₂ does not due to very low solubility) are in the minority—"shouted down" by the 70% insisting that they are right, regardless of the physics involved. Burn the heretic... ;)

An individual's tenure on RC has absolutely nothing to do with the quality of the information presented. It goes both ways. In one case, the "tenured" minority, might be right, but in the next case, the "tenured" minority may be very wrong, and is actually not a minority, rather another part of the majority. I read one argument conerning flow rate (up above) where "Trust us!" was specifically stated. This from an individual that has had 5 marine systems. Experienced yes, but, all due respect, I have ~250 systems running currently, the oldest ones predate his entry into this hobby. My my rock culture tank, predates Calore1's entry into the hobby. (converted from the original display role.) So much for tenure having much to do with anything... ;)

I think the OP has the numbers backwards though. From everything I see, the "low flow" proponents far outnumber the "high flow" proponents. That turns the table around. That is changing very slowly, over time; I am encouraged to hear that a few fish stores are finally grasping the concepts of multi-pass systems. The reason is rather simple, seperating folks from 40 year old rules of thumb, is the same as trying to seperate Linus from his blanket. But as Calore1 so graciously pointed out: That does not make it right. It does not even make it logical for a multi-pass system. In terms of a multi-pass system, there is only one argument for "low flow" that can't be shot full of holes, and that is the "energy" argument. However, with some modern pumps, that no longer holds water either; these pumps flow more and use less energy, than the old "majority" or "hearsay" pump recommendations. But again, is the majority right or wrong?


The only things that flow through the sump MUST accomplish are to adequately skim the display tank surface and ensure even heating. Both of these can be accomplished with 3-5 times tank turnover.Interesting. Looking at this, what is the definition of "adequate?" Is a low surface renewal rate, that allows a higher level of dissolved organics to be mixed back down into the display tank due to the overwhelming "make make up the difference " of the power heads, thus remaining in the tank perhaps indefinately—at all adequate, or something that could be considered adequate? Or is it simply one more piece of myth-information, based on hearsay, for which there is no logical explanation and a complete widespread misunderstanding (also based on hearsay) of the role of adjunctive power heads? The two cannot be additive (complimentary or supplementary) because they perform different functions in the system...

The "heater" point also presents some interesting ambiguity. A 500watt heater will impart 500watts of "heat" into the water. How fast the water is moving around the heater is absolutely irrelevant. The distribution of that "heat" will be by mixing and advection (movement of a substance or conserved property due to the bulk movement of a fluid, water in this case.) The low flow to "ensure even heating" is a single pass system way of thinking. In a single pass system, a "packet" of water has one shot at "being heated." In a single pass system your logic is very true, the lower the flow rate, the better. In a muli-pass system, this is not true. Dealing with heat is not a simple process, there are inputs, and losses, output of the heater, and time it takes to raise a total volume of water by 1°C (dependent on the heat input, "watts" or "BTUs" whichever way you wish to express it. However, the flow rate around the heater has nothing to do with any of that. If looked at in a logical manner, the higher the flow rate, the more evenly distributed that temperture rise will be.

Any more than that is simply heresay IME.Heresy? Or Hearsay? Either circle the wagons, and burn the heretics, or... believing something that someone told you that has no logical, or valid reasoning behind it? In the aquarium hobby, 70% of the information is hearsay, and the other 30% is considered heresy. (Using numbers already in use.)

Also, there is no relationship, nor correlation, between flow through the sump and skimmer pump capacity. One simply has no bearing on the other. If someone tells you there is, ask them to explain why and decide for yourself whether said explanation makes sense at all.Very true, the efficiency of the "skimmer" is not connected to the flow rate through the sump... ...or is it? On the one hand, what is important is the bubble size, and contact time within the skimmer body, the latter influenced by the flow rate through the skimmer, what flows past the skimmer is irrelevant: and no matter what the flow rate, more water will pass right by the skimmer than will actually be processed by the skimmer.

But there is another factor that the 70% don't bother with, ignore, or simply don't know about. That is the concentration of dissolved organics in the skimmer influent. The higher the concentration of dissolved organics in the skimmer influent, the higher the skimmer efficiency. Right off the bat, this debunks the use of recirculating skimmers, reducing them to the status of marketing hype. Adding 2 + 2 will always = 4. It won't equal 3, nor will it equal 5. Adding surface skimming/renewal rate + flow rate, what would be the answer to the concentration of dissolved organics in the skimmer influent? What would be the overall effect on gas exchange? What would be the overall effect on TOC (acknowledging the fact that the skimmer will only remove ~ 30% of the TOC regardless)

At the bottom of this there is one basic principle which low flow arguments cannot touch: in a multi-pass system, the higher the recirculation, the more efficient the system is overall. All the anecdote, the "done it for years with no issues" comments cannot touch it. It simply is. There is no system (enclosed, seperated from the open ocean) that does not have issues. To what degree those issues present themselves, and what you have to do to mitigate them, covers a very wide "bandwidth."

The question is not about who is right and who is wrong, rather about do we accept adequate, or strive for excellence? Everyone is looking for excellence, the difference is in how you get there, and how many of what types of problems you have to deal with. Adequate vs more than adequate vs designed for maximum efficiency (corner overflow vs 18" back overflow vs C2C for instance, or durso vs herbie vs bean.)

The other thing is: if you have never done it, you simply don't know, and it is all hearsay. If you have done it, and "it made no difference" perhaps you weren't looking at the right things, rather what hearsay says to look for, or you did not do "enough of it" to make a difference, because it all works hand in hand.

OP: To get away from the emphasis on the "flow rate" that is being enforced in this thread... If you want to run 10x or 100x the system volume through the sump, there is no valid reason not too. Just make sure your system is designed to take advantage of it. Long overflows, with flat weirs, a wide sump, siphon drain system, etc.

I don't see what the problem is with the sump overflowing using a siphon system. If you want to know a relationship between the "herbie" modification and a "traditional" 2 pipe siphon system (using elbows) the herbie is going to create more power out drain down, and there is nothing that can be done about it. Sump overflows are prevented by a passive failsafe: enough space in the sump to contain all power out drain down, regardless of the amount of said drain down. The drain system type has nothing to do with that; it is a sump design question, not a drain system question.

[ca1ore]

WOW .....

I'd suggest that there is likely a correlation between 'tenure' and quality of advice; at least I have found it to be so.

70% was illustrative, not literal .... and FWIW I'm in that minority that rejects the notion that a skimmer has much if anything to do with O2 levels.

Also, I think perhaps you missed my point on heating. It's a somewhat academic one, I suppose, but if one takes flow to a low enough extreme it is certainly possible for a heater located in the sump, even if of adequate wattage, to fail to maintain a proper display temperature because heat loss exceeds heat input. I actually experimented with this some years ago. Clearly there are many variables, including ambient room temperature, but it is easy enough to demonstrate experimentally.

Probably more than than the OP was looking for, though ...... :lol:

[kckinwa]

Wow! Lots of conversation, love it thanks for all the feedback. In the end I found a 120 gallon oceanic with dual corner overflows. The tank has a 1" bulkhead and a 3/4" bulkhead in each of the overflow boxes. My first step is to remove and re-seal all the seams. Then I will start my sump design as the current sump that I have I built for a 75 gallon that I started with back 10 years ago. The sump was perfect for power down and not overflow, I never had a flood and we lost power several times. Lucky for me I had a generator to keep the system going as we lost power for 4 days two different times. I also am in the process of constructing the stand using the DIY tank stand thread here. The stand is going to be roughly 48x24 so I should have lots of room in the cabinet for a significantly larger sump. I am also researching the use of a algae turf scrubber. I am in no hurry as I have lots of design and equipment research to still do. That being said, again thanks for all the input. If anyone has any suggestions they will be greatly appreciated. I will update with photos as I go.

Thanks,
Casey

[uncleof6]

Yeah, sell the reef ready 120 and get a non reef ready 120. The reef ready tanks are just as obsolete as the 10 year old sump you wish to replace.

Does the tank need to be resealed? If not, don't mess with it. If the tank is leaking, resealing is not enough, and it must be rebuilt completely.

[kckinwa]

?????? I am not sure I understand.....reef ready....obsolete? Every lfs you go into sells reef ready. My understanding is that reef ready just means that it has built in overflows. I thought it was the other way around and that the hang on back style of setups was the old method. If I went with a non reef ready tank then I would have to come up with some other way of getting water from the DT to the sump, in other words make a non reef ready tank....reef ready. I am not sure if the tank leaks or not, I have just been told that anytime you buy a used tank it is a good idea to replace the seals.

[uncleof6]

?????? I am not sure I understand.....reef ready....obsolete? Every lfs you go into sells reef ready. My understanding is that reef ready just means that it has built in overflows. I thought it was the other way around and that the hang on back style of setups was the old method. If I went with a non reef ready tank then I would have to come up with some other way of getting water from the DT to the sump, in other words make a non reef ready tank....reef ready. I am not sure if the tank leaks or not, I have just been told that anytime you buy a used tank it is a good idea to replace the seals.

Exactly! The manufacturer says this is how we make money. Obsolete yes. RR means small overflows, small useless holes (in most cases.) These tanks are inefficient in surface skimming/surface renewal, and make implementing better drain systems and return systems more complicated than necessary. Even with siphon systems dual overflows are problematic and don't balance out.

They are in the stores, because the manufacturers won't change something that sells, and the stores have them because they "sell." Folks buy them, because they think they should. So until folks stop buying them, they will stick around. That does not make them any less obsolete. They are made obsolete by C2C overflows (toothless) and siphon drain systems. This is something that some manufacturers/builders will do, at additonal $$, but the cost—is the same as doing it "their way." The motivation here is profit margin, not what is really known to be better for the system overall.

True, if you buy a non-reef ready tank, you have to build the system yourself, however the system you build (if you do selective reading) will be more efficient, and provide a better environment for your critters.

Never buy a tank, unless you know it does not leak. There are generally reasons folks dump tanks, and among them are they leak or they don't work as expected. Used tanks are like used cars: Lemons are more prevalent than anything else.

A used tank, does not necessarily need to be resealed. It is a lot of work, when done right, and can do more harm than good, if not done right. As I said, if the tank is leaking (and you should have found that out before you hauled away someone else's garbage, in which case they should have paid YOU!!) it needs to be completely rebuilt.

[SGT_York]

The dual overflows are tricky and the small teeth on the reef ready overflows are very inefficient. It was a good concept back in the day, but there are much better ways to run a reef. Considering you already bought the 120 I'm going to assume you intend to keep it.
Issue number one, with only two holes in each overflow it is difficult to get good flow you can run the 1" pipes as durso's and the 3/4" as returns. The challenge is you can't get more than 600 GPH or the pipes will gurgle like crazy (loud enough to make your wife hostile to the hobby) While 600 is good enough for an ok reef, it just isn't enough flow for me. I like to keep my water clean which requires lots of water going to the skimmer. I prefer the 10x turnover.

So your options with two overflows, ripping them out and rebuilding, or implementing a herbie system with your return behind the tank. My preferred approach for reef ready tanks. One complete herbie in each return works well. use the 3/4 as the siphon line and 1" as a durso. Bit complicated to get dialed in but works well. There are a few other options like a single siphon but I'll save that unless you really want to know. The herbie really helps get enough flow so when you blow off the detrius in your rocks it get's sucked into the overflow. Powerheads keep it suspended but without good flow it just settles somewhere else and breaks down into nitrates and phosphates. With a dual herbie you can easily run ~1500 GPH, at which time the overflow teeth will be under water. (which is why the non reef ready tanks are much better coast to coast C2C without teeth)

Issue number two is the location of the two overflows add the challenge for a good sump. A single overflow like C2C is great at having an effective sump and plumbing system. (but that is a discussion for a different tank)

Issue number three is the overflow teeth themselves. Originally they were intended to keep fish and snails out, but they significantly increase the display tank water height and only pull a small fraction of water directly from the surface (due to the increased water height caused by the teeth). the proteins that become ammonia/phosphate float, the teeth added a sticky film on the water surface that is a challenge to get out with no teeth and good surface flow that surface skim is a thing of the past which significantly improves water quality.

P.S. your overflow teeth appear much wider than the standard reef ready tanks which is a good thing.

[uncleof6]

The dual overflows are tricky and the small teeth on the reef ready overflows are very inefficient. It was a good concept back in the day, but there are much better ways to run a reef. Considering you already bought the 120 I'm going to assume you intend to keep it.
Issue number one, with only two holes in each overflow it is difficult to get good flow you can run the 1" pipes as durso's and the 3/4" as returns. The challenge is you can't get more than 600 GPH or the pipes will gurgle like crazy (loud enough to make your wife hostile to the hobby) While 600 is good enough for an ok reef, it just isn't enough flow for me. I like to keep my water clean which requires lots of water going to the skimmer. I prefer the 10x turnover.

So your options with two overflows, ripping them out and rebuilding, or implementing a herbie system with your return behind the tank. My preferred approach for reef ready tanks. One complete herbie in each return works well. use the 3/4 as the siphon line and 1" as a durso. Bit complicated to get dialed in but works well. There are a few other options like a single siphon but I'll save that unless you really want to know. The herbie really helps get enough flow so when you blow off the detrius in your rocks it get's sucked into the overflow. Powerheads keep it suspended but without good flow it just settles somewhere else and breaks down into nitrates and phosphates. With a dual herbie you can easily run ~1500 GPH, at which time the overflow teeth will be under water. (which is why the non reef ready tanks are much better coast to coast C2C without teeth)

Issue number two is the location of the two overflows add the challenge for a good sump. A single overflow like C2C is great at having an effective sump and plumbing system. (but that is a discussion for a different tank)

Issue number three is the overflow teeth themselves. Originally they were intended to keep fish and snails out, but they significantly increase the display tank water height and only pull a small fraction of water directly from the surface (due to the increased water height caused by the teeth). the proteins that become ammonia/phosphate float, the teeth added a sticky film on the water surface that is a challenge to get out with no teeth and good surface flow that surface skim is a thing of the past which significantly improves water quality.

P.S. your overflow teeth appear much wider than the standard reef ready tanks which is a good thing.

The Herbie modification does not use a Durso style standpipe. It does not matter how many folks try to do it that way, it is not safe. The herbie has a single siphon, and a DRY emergency. That is the only safe way. This applies to dual herbies as well, (practically my brainchild, a few years ago,) but they are NOT STABLE, and are impossible to balance without doing more things (creating a single point of failure) that are unsafe.

As far as RR tanks go, I can't see a good reason NOT to rip out the overflows, plug existing "tiny" holes, and put in a C2C, and use a stable drain system, which the herbie is not. RR tanks are obsolete as they come from the manufacturer.

A 120 is a great tank, dimensionally and visually, it is a crying shame to run it with the RR handicap.

[kckinwa]

So your saying ("The herbie has a single siphon, and a DRY emergency. That is the only safe way.") a single not double herbie is the only safe way?

[kckinwa]

would this work (pic 1) or would I have to remove the 2 origional boxes and go wall to wall (pic 2) would have to put bracing in the overflow box for the c2c.

[SGT_York]

Uncle's comments are based on the durso stand remaining dry is the only safe way, no issue with doing a dual herbie just running a durso vs dry is his main point, if you can't tell we have had this discussion several times.

The argument is based on the possibility of the durso getting blocked, which does happen, so you can either run it dry as Uncle suggests to everyone (which is good advice) I tend to think of the herbie with Durso as a safer option than a plain durso, and prefer the stability of the trickle, to mitigate the risk I use other factors for safety, such as a dark lid over the overflow and strainers on each pipe opening. The major risk factors are snails, siphon lines are like magnets for snails. So you need something for sure. A typical durso the snails just get flushed to the bottom with a rare occasion that a snail can fit through the pipe but get stopped at the bulkhead. A siphon is far more prone because the snails get stucks at the gate valve (which is much smaller than the bulkhead)

I've had four snails stuck in a bulkhead and only one ever stuck in the durso with my off and on tanks for the last 10 years (only five with a dual or joint herbie). By far the best method was the solid lid, it keeps fish and snails out of the overflow and the dark color prevents algae buildup. Never had an issue since I added the lid. So my risky behavior is acceptable to me based on my usage of a lid rather than a dry durso. And certainly safer than the traditional single durso and return in the overflow old concept.

With your pictures in the above post adding a C2C is a great idea, I'd go with the 1st one just so you aren't loosing all that space in your display.

[kckinwa]

Thanks for the insight. I was thinking I like the 1st one also. I then thought maybe if I ran the front piece of the c2c addition to lap over the front of both corner overflows so as to cover the teeth on the front of the old overflows and leave the teeth on the sides of the old overflows so the water can travel from the center addition to the corner boxes and then to the sump.I would also cap the overflow with a lid as you did. Then I could use two of the 1" and one of the 3/4" bulkheads for drain and the remaining 3/4" plumed to the center of the addition c2c for return. Or am I going to have issues no matter what with the current tank

[kckinwa]

I think I have found a solution to my plumbing. I found a guy on youtube that instead of using a emergency pipe he is using a float switch controlled pressure regulator and as a last resort a float switch to shut off the pump. All controlled with a Apex.(https://www.youtube.com/watch?v=K1sUURZiXfY) This would allow me to avoid the stagnant water in one of the two overflows and also allow me to still utilize both of my returns. Has anyone tried this? What do you all think?

[trhaynes]

Just my 2 cents. I ran the exact tank with 1800 gph through the stock corner overflows using dursos. It was quiet and easy. Build your own durso, build it taller so the down facing elbow is higher. Creating less of s cascade into the overflow box. Use a strainer on the intake of the durso. Do not drill a hole in the top of the cap, instead a larger hole through the side, now you can twist the cap to regulate incoming air. Fabricate a cover for the overflow box to keep snails out. Simple cheap, no removing and rebuilding. I ran both returns using them more for surface agitation.

[trhaynes]

Your fail safe is good no matter what drain style you choose.

[uncleof6]

So your saying ("The herbie has a single siphon, and a DRY emergency. That is the only safe way.") a single not double herbie is the only safe way?

The herbie with a DRY emergency is the only safe way. Absolutely. Folks do it other ways, but that does not make those ways safe, or even advisable in anyway. Again, it just means folks do it.

Dual herbies is not a safety risk, it is a balance problem, and it does not work as advertised. The "single" means a 1 to 1 ratio, not 2 to 1, or any other machination, although the 1 to 1 ratio can be achieved in a couple different ways. Depends on what you have to work with. I believe I coined the concept several years ago, as an alternative to attempting a BA system with dual overflows; yes I am knocking the concept...

[uncleof6]

Just my 2 cents. I ran the exact tank with 1800 gph through the stock corner overflows using dursos. It was quiet and easy. Build your own durso, build it taller so the down facing elbow is higher. Creating less of s cascade into the overflow box. Use a strainer on the intake of the durso. Do not drill a hole in the top of the cap, instead a larger hole through the side, now you can twist the cap to regulate incoming air. Fabricate a cover for the overflow box to keep snails out. Simple cheap, no removing and rebuilding. I ran both returns using them more for surface agitation.

Physics says that a durso (open channel) will start making noise and become unstable when the pipe is 1/4 full of water. How your system is actually performing is based on the size of your dursos. If they are 1.5", this occurs around 350gph, making a total of 700 gph for two.

It does not matter where the air hole is, or how the air enters the standpipe, it will not change the dynamics of the standpipe style. You cannot beat the physics. It is possible to tweek dursos much higher, close to siphon, by reducing the amount of air in the line. However, the higher they are tweeked, the more unstable they become, and they will never be silent. Also, the higher they are tweeked, the more unsafe the system becomes.

If one is going to tweek them high enough to handle 1800gph overall, the only sensible thing to to is convert to a siphon system. Using a durso system is counter intuitive, and it doesn't matter what you do, you cannot beat the physics.

Which brings us to the "corner overflows" which more than likely will not handle 900 gph each, quitely, and doing weir calcs on them would be rather complicated considering the teeth. I suspect a flow meter is needed on the pump outlet to find out what that particular tank is/was actually flowing.

[uncleof6]

I think I have found a solution to my plumbing. I found a guy on youtube that instead of using a emergency pipe he is using a float switch controlled pressure regulator and as a last resort a float switch to shut off the pump. All controlled with a Apex.(https://www.youtube.com/watch?v=K1sUURZiXfY) This would allow me to avoid the stagnant water in one of the two overflows and also allow me to still utilize both of my returns. Has anyone tried this? What do you all think?

The only reasonable failsafe, is a passive fail safe, or a single mode of failure which results in the system being safer, not more of a flood risk. Any mechanical or electrical device used as a fail safe, needs an addtional passive failsafe, or it is just a waste of time. Youtube is entertaining to watch, but the value, and often the validity, of the information you get from youtube is not very high. It is an example of "striving for 15 minutes of fame..." Examples of passive failsafe: sump volume for power out drain down: no failure mode. Air vent line on the open channel of a BA system: One failure mode-- plugged air vent line, makes the system safer by tripping to siphon. Or a DRY emergency, that can only fail if water is flowing in it... common sense says that it will be obvious when the dry emergency kicks in, it will suck air and make noise. Intervention will most likely occur before the now flowing emergency has the opportunity to become occluded. BA's system mitagates that risk however, with air vent line failsafe.

The bottom line is do it right, don't hunt up shortcuts that may be more convenient, but won't be what they seem to be.

[SGT_York]

I concur electronic failsafes are a fine third barrier, but by themselves they will fail (as will everything else). You want a system that when it fails you know about it and there is a backup to prevent disaster (called defense in depth). With this one you will only know it failed when either your living room is wet or your return pump is destroyed. The Herbie or BA are better options. A split or joint herbie is a marked improvement over the electronic system. BA is best of all.