Refugium gravity return to display, need some math experts,,

[ReefGoatfish]

good forum , this is my first Question, i have a 23 gal refugium, 40 gal sump, 120 gal display tank, the bottom of the fuge is just above the top of the display in a closet next to the tank, there's a rio2500 pumping through 3/4" vinyl into the fuge from the sump and a 1" bulkhead at the waterline at the top of the fuge connected to 1" pvc to 1" vinyl down into the display (vinyl to move around as to direct the flow at who i want in the tank) currently it barely pees back into the display, i'e got the rio cut back about 3/4's of the open flow, the headloss calc has the rio at 245 gph, this is my frst go at this, my thought at this point is to put 3 more 1" bulkheads plumbed into the 1" pvc going back to the tank, and put in an overflow with teeth to suround the 4 bulkheads, i attached i diagram of what i have so far and i'll send another about what thinking for a fix directly, any thoughts ????? thanks for your time,

[ReefGoatfish]

and here's my idea to fix it , hows' my math ??

[tkeracer619]

1) 1" drain should flow at least 600gph. There is no reason for 4 bulkheads. Water in will equal water out.

[tkeracer619]

Does it overflow if you open up the ball valve?

[ReefGoatfish]

with the one 1" bulkhead ,and the rio on full open it looks like it will over run the fuge tank ,the level keeps going up until i turn it way back, i was thinking it would because i have it going straight for too long out of the fuge before it turns down into the display, i was going to add the overflow in the fuge tank to keep things from blocking the return hole , only got one as of now!

[dzhuo]

Originally Posted by ReefGoatfish

this is my frst go at this, my thought at this point is to put 3 more 1" bulkheads plumbed into the 1" pvc going back to the tank, and put in an overflow with teeth to suround the 4 bulkheads, i attached i diagram of what i have so far and i'll send another about what thinking for a fix directly, any thoughts ????? thanks for your time,

I wouldn't do that. Your second design is slightly better than your original one but it's still not fail safe. The problem is you still have a single return to the display and if there is anything blocking the flow after the join , you are looking for a flood. I have had all kinds of blockages from snails, dead fish, macro algae, etc and if I don't have en emergency, I would have to deal with lots of wet flooring. The 4 bulkheads and overflow will provide a little better redundancy but since they are all joined to a single return, you are reduced to a single point of failure.

If I were you, I would just use a single 1" bulkhead just like your original design but I would lower the water line in the fuge. I would use this as the primary return. I would then cut another 1" hole a couple of inches above the primary and use it as an emergency. The emergency should be dry at all time except when the primary is block at which case the water will raise and overflow into the display.

The second thing you need to do is make sure the display can handle the extra water. Finally, you need to make sure both your display and the sump can handle the extra water in case of power lost. Your fuge is essentially split into both the display and sump.

[ReefGoatfish]

thx for the advice dzhuo, an emergency is a good idea and it needs to be the same as the main for it to work, but my problem still stands as the flow is very very slow, i believe it's the fact that the return goes level for too long before dropping but im not sure about that ,and i have plenty of room in the sump for power off, i've done many tests, so the question is, why am i getting such poor flow out of the 1" return from the fuge??

[dzhuo]

The long run off will probably add a bit of pressure but it won't affect the return in any significant way. The capacity of your return is determine primarily by your Rio which I assume is just weak (you are pushing +5' up). If you have a ball valve, I would open it completely, a 1" siphon should handle it just fine given you have a 1' drop to the display. Have you tried it? I am also not a big fan of Rio pumps (especially as return).

[ReefGoatfish]

ok, i haven't let it the water get too high in the fuge tank as i think i put the bulkhead very high in the tank, i'm just nervious about it overflowing , but i can setup a bench test outside with the exact conditions and let her rip, i think if this is fine, i'll use the existing bulkhead as the emergency and put one lower for the main and add the overflow box like i was going to anyway, i thought a rio was i good pump, it filled (from the sump) the fuge tank in about 5 mins is that a little slow, turnover for fuges should be slow correct? but how slow? so are rio pumps unreliable? and thanks for you time,

[dzhuo]

Originally Posted by ReefGoatfish

i'll use the existing bulkhead as the emergency and put one lower for the main and add the overflow box like i was going to anyway

That sounds like a fine plan.

Originally Posted by ReefGoatfish

i thought a rio was i good pump, it filled (from the sump) the fuge tank in about 5 mins is that a little slow, turnover for fuges should be slow correct? but how slow? so are rio pumps unreliable? and thanks for you time,

I have never personally used a Rio as return but I have seen enough cases regularly of how unreliable a Rio can be. If you do a search here, you will probably find lots of discussions. As for turnover of the refugium, you will probably want it to be slow in your case. You have a 1' drop to the display so any extra force will create lots of splashes and noise. What are your plans?

[ReefGoatfish]

thx for all your input dzhuo, 1st i didn't let the level in the fuge get high enough, in testing it outside it Didn't overflow the tank with the rio at full , and with the head pressure drop from the height of the fuge tank from the sump i think the turn over rate will be just right, as for my plans my thinking was (and tell me if im wrong) i wanted to put the return from the fuge about half way down in the display as to direct the flow straight at filter feeding corals, is that thinking sound ? and if i wanted even more flow could i put an addtional 1" bulkhead (haveing a matching one for an emergency) and get a bigger pump, would that create more flow coming out into the display , if i wanted to blow more fuge water at corals, if that theory is sound, i guess at some point the teeth of the overflow box in the fuge maybe the limiting factor, i have one more question, if the teeth of the over box goes up to the underside of the fuge tank top( it's an acrylic tank with a partial top ) what kind of clog could i even get, no snail could even get at a bulkhead, unless the teeth them selfs get cloged in which case my emergency should be outside the teeth of the overflow box , wow , that was a mouth full :0 hope you got it once again loads for your time ,,,,

[dzhuo]

Originally Posted by ReefGoatfish

in testing it outside it Didn't overflow the tank with the rio at full

Good. That's what I expected.

Originally Posted by ReefGoatfish

my plans my thinking was (and tell me if im wrong) i wanted to put the return from the fuge about half way down in the display as to direct the flow straight at filter feeding corals, is that thinking sound ?

That sounds reasonable but now that we know the return will be submerged under water, you might run into additional issues such as noise. What happen is if your primary is not a full siphon, it will suck in air so you will need to create an air escape hole or maintain the primary as full siphon at all time (this will be my preference). There are few (minor) things you need to change in order to make this work but before I go into details, is there a reason you want to gravity feed the display?

Originally Posted by ReefGoatfish

if i wanted even more flow could i put an addtional 1" bulkhead (haveing a matching one for an emergency) and get a bigger pump, would that create more flow coming out into the display

Adding more bulkheads wouldn't create any additional flow but using a bigger pump would. You can't drain more than what you put into the fuge. The pump is what controls the capacity.

Originally Posted by ReefGoatfish

i have one more question, if the teeth of the over box goes up to the underside of the fuge tank top( it's an acrylic tank with a partial top ) what kind of clog could i even get, no snail could even get at a bulkhead, unless the teeth them selfs get cloged in which case my emergency should be outside the teeth of the overflow box , wow , that was a mouth full :0 hope you got it once again loads for your time ,,,,

If you keep snails at all, it's better to prepare for when they eventually find their way into the fuge. Keep in mind that some of the snails we keep will readily reproduce in our tanks and a few of them have planktonic larval stage which could travel to any part of the tank, sump or fuge. Once settle, they can grow rapidly. I don't understand the rest of your questions regarding overflow teeth but as long as your emergency can operate independently from the primary and has equal (or more) draining capacity, it should be fine anywhere you want to drill it.

[jjk82901]

you may want to keep the fuge at the low flow rate to increase dwell time of the water in the fuge. if you want more water movement if the fuge, you could add a small powerhead.

[ReefGoatfish]

Originally Posted by dzhuo

That sounds reasonable but now that we know the return will be submerged under water, you might run into additional issues such as noise. What happen is if your primary is not a full siphon, it will suck in air so you will need to create an air escape hole or maintain the primary as full siphon at all time (this will be my preference). There are few (minor) things you need to change in order to make this work but before I go into details, is there a reason you want to gravity feed the display?.

ok first thx for the help ! the reason for the grav fuge is where it is (above the display in a closet about 3 ft away , easier to pump water in it from the sump and the school of thought, better for the critters to return to the tank without going through a pump, and i know this discussion goes both ways)
now im curious about the full siphon or not, i'm a little vague on this, i will say having the return from the fuge about a foot down in the tank there was no noise from the return in the tank or from the bulkhead at the fuge tank, as the water level is over the top of the bulkhead hole. but this brings up an other situaton, that is the display is an All-Glass 120 w/dual overflows, with their megaflow return and drain tubes , i have 2 3/4" vinyl tubing coming from 2 800 gph pumps and 2 1" drains coming back to the sump (40 gal), putting the drains under water causes a lot of noise as there is a lot of air from the raiser tubes ( the Megaflow setup) is that a full siphon??and what did you mean by primary?? (the drain, other than the emergency) now just goofing around i tied the to drains together and got much less air and holding my hand over the now one drain tube in the sump i get no air , quiet ,but curious? I"ve been following another thread about the quiet drains and i guess what i've done is a"Herbie", is that right? so my thinking was putting a gate valve on the one drain after their tied together, hence, backing it up a bit more , but i don't know why it gets quiet , and this worries me, i have a good understanding about plumbing and pressures, i've been reefing for about 15 years but this is my first big tank w/sump, hope this wasn't too long winded, if i wasn't clear enough i can draw a pic of just what it looks like ,,,,,again thx for your time

[das75]

Have similar.

Surprisingly found with a 1" bulkhead can only flow about 200gph when mounted high on the side. Added a 300gph powerhead and for extra movement and seem a increase in chaeto growth rate.

[dzhuo]

Originally Posted by ReefGoatfish

better for the critters to return to the tank without going through a pump, and i know this discussion goes both ways

If this is your primary reason of gravity feed, I would suggest that you leave this sort of micro-optimization for people who's silly enough to believe it will make any impact. Almost all water bound critters / pods will survive through your pump's impeller. Not to mention the planktonic stages of lots of worms, pods, shrimps, etc are so tiny the pump don't really have a chance to harm them. Get your light, water parameters and flow right. These are much more important than saving a few pods.

Originally Posted by ReefGoatfish

is that a full siphon??

If there are lots of bubbles and noise, you are probably not running a full siphon.

Originally Posted by ReefGoatfish

I"ve been following another thread about the quiet drains and i guess what i've done is a"Herbie", is that right?

That's what I tried to direct you to and by primary, I mean the primary drain in as in the Herbie / BeanAnimal style overflow. The primary principle behind this overflow is to slow the drain enough to create a full siphon. Typically you do this by using a ball or gate valve on the return pump (in your case, the return is actually from the fuge above the display tank) and another ball valve on the primary drain. You dial (using the ball valve) the primary drain just a little bit slower than the return. Slowly, the water in the display tank will raise and create a full siphon (which is completely silent). Since the drain capacity is lower than the return, the water level will continue to raise and pressure will build up on the overflow. The increased pressure will slowly increase the drain capacity and eventually the drain and the return will balance. Even if you don't have enough vertical space to separate the primary and emergency drains, you can continue to let the water to raise in the display and the emergency will handle the left over capacity. Since the raise is so slowly, water from the emergency is very low and thus no concern of noise too.

Advantages of this overflow are: Self-adjusting, fail safe and completely silent. I hope this answers your question. If you keep one very simple principle in mind, everything else should follow: You can't drain more than your return. In other word, your drain is controlled primarily by the return, not by how many and how big each bulkheads are. Obviously, the drain capacity needs to equal or greater than your return capacity but that's a given.

If this still doesn't answer your question, please provide a few photos of your complete drainage and return, I (and others) will be happy to help you out.

[ReefGoatfish]

Originally Posted by dzhuo

If this is your primary reason of gravity feed, I would suggest that you leave this sort of micro-optimization for people who's silly enough to believe it will make any impact. Almost all water bound critters / pods will survive through your pump's impeller. Not to mention the planktonic stages of lots of worms, pods, shrimps, etc are so tiny the pump don't really have a chance to harm them. Get your light, water parameters and flow right. These are much more important than saving a few pods..

yeah dzhuo that wasn't the reason for the fuge setup this way, it was because mostly from the logistics of where everything sits

Originally Posted by dzhuo

If there are lots of bubbles and noise, you are probably not running a full siphon.



That's what I tried to direct you to and by primary, I mean the primary drain in as in the Herbie / BeanAnimal style overflow. The primary principle behind this overflow is to slow the drain enough to create a full siphon. Typically you do this by using a ball or gate valve on the return pump (in your case, the return is actually from the fuge above the display tank) and another ball valve on the primary drain. You dial (using the ball valve) the primary drain just a little bit slower than the return. Slowly, the water in the display tank will raise and create a full siphon (which is completely silent). Since the drain capacity is lower than the return, the water level will continue to raise and pressure will build up on the overflow. The increased pressure will slowly increase the drain capacity and eventually the drain and the return will balance. Even if you don't have enough vertical space to separate the primary and emergency drains, you can continue to let the water to raise in the display and the emergency will handle the left over capacity. Since the raise is so slowly, water from the emergency is very low and thus no concern of noise too...

thanks for putting it in those words , because my natural reaction was to do just that with the drains, then reading the herbie thread confirmed it, i was little unsure of the reason til you explaned it , i'm going to try using 2 gate valves on the 2 drains from my display to the sump, but connecting them with a cross over pipe before the valves to balance it out to stop the constant adjusting of each valve to keep each overflow the same,(car exhausts do this) my thinking is with 2 outlets a clog is less likely than if i use one valve, is that sound thinking ? this build is fun and informative as i am in no hurry, have the money to experiment, funny thing, i was testing the fuge tank outside with the hose and checking gph trying to get the right speed, i checked the drain, got a number, ok, then i started to check the water in speed and hit myself on the head and said " you dope it has to be the same has whats coming out !" duh, so i got it at 250 gph, does that sound like a good turn over for a fuge ??

the grav fuge is working great, useing 2 1" bulkheads for each main and emergency, (less chance of a clog having 2 for each) useing a smaller nozzle for the main drain at the display, that makes it a full siphon, and the emergency is full 1" all the way with the drain end sitting above the water level in the sump, it makes noise at the tank and in the sump , to tell me it's being used, when all working right and clear it doesn't use the emer ,

thx a lot for all your help, i think next i'm going to start a diy LED setup with cree's, haven't bought anything yet , been reading threads, you have any thoughts on this ??? once again thx for your time

[dzhuo]

Originally Posted by ReefGoatfish

i'm going to try using 2 gate valves on the 2 drains from my display to the sump, but connecting them with a cross over pipe before the valves to balance it out to stop the constant adjusting of each valve to keep each overflow the same,(car exhausts do this) my thinking is with 2 outlets a clog is less likely than if i use one valve, is that sound thinking ?

But you still plan to have an extra emergency drain that's not connected to the primary right? If so, the plan sounds fine. If not, I would use one drain for primary and another as emergency. In other word, I wouldn't cross connect the 2 drains.

Originally Posted by ReefGoatfish

thx a lot for all your help, i think next i'm going to start a diy LED setup with cree's, haven't bought anything yet , been reading threads, you have any thoughts on this ??? once again thx for your time

I don't have much experience with LED but it seems like a fine choice given the popularity and the success some folks have. I run MH myself.