Algae Scrubber Basics

[redneckgearhead]

That is good to know!

[Floyd R Turbo]

Originally Posted by Robert Patterso

Just thought I would give a little info. about the sump system for the 900+ gallon fish system I plan to build the ats for the lfs I work part time at. The sump is 72Lx24Wx36dp. The bioball area itself is 36Lx24Wx36dp. The water line is approx. 16" from the top. I can go as tall as I want but to tall would be just over kill. My plan is to build 2 screens 24x24 with 12 t5s. My thinking is lighting the 2 screens in the middle with 4 bulbs that way I won't need reflectors because they will light both screens. Of course the outside bulbs will have individual reflectors.

Do you guys think that will be enough or should I add more lights. The owner says he will supply me with whatever I need. My thinking is that if the 2 screens are close enough to each other that the bulbs in the middle won't need reflectors. Otherwise I can add 4 more bulbs with reflectors. What you guys think?

Any input would be appreciated before I get started on this project

Thanks in Advance

I just wanted to comment on the center-lamp idea. When you take a 2-screen system and put lamps in between the screens, so you have lamps-screen-lamps-screen-lamps, the center lamps have about 1/4 of the effectiveness. The reason is that #1 you are splitting the lamps between 2 screens, and #2 you lose all the light power that is not directed/reflected one way or the other. Since no one makes a reflector that can effectively take a linear light source and direct 50% of it one way and 50% the other way, you end up with a bare lamp in between the screens. So it sounds great on paper because it saves real estate but to get the effectiveness of 1 reflected T5HO on the outside, you would need 3 or 4 lamps stacked up next to each other on the inside.

This is why I am not a fan of the center-lamp design. You just can't squeeze any more lumens out of a lamp. You are way better off going with 48" lamps, or just making 2 24" units. If you made a 4-4-4 unit, you would be better off making two 3-3 units, because you can reflect all the lights and maximize the power to the screen.

Also T5HO fixtures are 24" long, but the portion of the lamp that is actually illuminated is more like 20", so having much wider than a 22" screen doesn't do a whole lot. If you use T5HO waterproof endcaps, you end up with 19-7/8" exposed lamp.

Also like srusso said, you have a maximum lamp spacing of about 3 or maybe 4 inches. So 3 lamps on a side means a 12" x 22" screen, two of those means you have about 24x22 scrubbing power or about 525 gallons of filtering capacity. Having your lamp spacing a little wider than 3" will decrease that a little, but using T5HO you're ahead of the game, so that would effectively filter a 500 gallon fully stocked tank. So if you have 900 gallons and it's half stocked (or only moderately fed) that will probably work well.

Hope that helps

[Gandolfe]

I have 2 screens 13.5 x 10 that i bought and was thinking about doing a tee with both screens, if i have lights on both sides of screens and only 2" or 3" between the screens with that be enough light to grow algae on both screens or should i just glue them together and make one double screen

[Floyd R Turbo]

Originally Posted by Gandolfe

I have 2 screens 13.5 x 10 that i bought and was thinking about doing a tee with both screens, if i have lights on both sides of screens and only 2" or 3" between the screens with that be enough light to grow algae on both screens or should i just glue them together and make one double screen

You kind of lost me. Maybe try that again.

The one part I can pick out of this is the double-screen: no. Don't double up the screen, it doesn't do anything for you unless you have massive flow, capability for 3D growth, and cleaning between the screens. Even then, you're at the point of diminishing returns.

[JohnnyB in SD]

Originally Posted by srusso

Decided to clean the screen today, on day 6. Dosed iron pills today... Let's see how this stuff works.

Attachment 158008

Attachment 158009

Not bad for six days growth for only being my first week with new scrubber version 4.

FYI- I removed the splash guard... It just wasn't needed... IMHO the new slot tube came out nice and straight.

Hey srusso,
I notice the top of your screen is very clean. Is that just because it's all in the slotted pipe or are you doing something to block the light there?

[6Speed]

Originally Posted by OodleyBoodely

I'd be interested in seeing what you come up with. I removed my 6g from the 37gallons sump, and, I don't have any filtration in it now except the 6lb live rock in the tank. It has a 5g bucket as a sump and it is very cramped and limited for space, but, I'd love to put a scrubber on this if I can come up with a decent design to use. Please do post here when you do yours for your Elos.

I will let you know soon as I come up with some plans.

For now here is a schematic of the sump (not drawn by me. credit to the creator is on the schematic):



I hope I can describe this well enough to make sense. If you're not familiar with this sump, the layout is:

- far left compartment: rodi topoff reservoir
- front two 5"x4" compartments are for a filter sock and refugium
- middle compartment just behind the front two is for return
- rear-most 2" wide compartment with the slanted baffle is for the outlet of the overflow to dump into.

So my two options are:

1. to have a vertical scrubber fed by the overlow cascading water down into the 2" wide area behind the slanted glass

or

2. have a vertical scrubber above the two 5"x4" compartments and have some sort of tray or splash guard that would funnel all of the water off the end of the scrubber into the sock filter compartment (left 5"x4" compartment on front).

Keep in mind that I run my return compartment water high, almost to the top of the 9" tall sock/fuge compartments. Basically the slanted baffle in the rear of the sump is of minimal use because the water level is well above it.

note: the glass pane in-between the two small 5"x4" compartments on front of the sump actually has a gap at the bottom for water to flow under from the sock filter to the refugium, before it returns to the larger compartment behind them via the circular hole on the back piece of glass.

[srusso]

Originally Posted by JohnnyB in SD

Hey srusso,
I notice the top of your screen is very clean. Is that just because it's all in the slotted pipe or are you doing something to block the light there?

I left the top of the screen without being roughed up. A side from that it's probably b/c my new scrubber is only about 1 week old. As it ages it will grow more at the top.

It's also growing where the light is most intense.

[Robert Patterso]

Originally Posted by Floyd R Turbo

I just wanted to comment on the center-lamp idea. When you take a 2-screen system and put lamps in between the screens, so you have lamps-screen-lamps-screen-lamps, the center lamps have about 1/4 of the effectiveness. The reason is that #1 you are splitting the lamps between 2 screens, and #2 you lose all the light power that is not directed/reflected one way or the other. Since no one makes a reflector that can effectively take a linear light source and direct 50% of it one way and 50% the other way, you end up with a bare lamp in between the screens. So it sounds great on paper because it saves real estate but to get the effectiveness of 1 reflected T5HO on the outside, you would need 3 or 4 lamps stacked up next to each other on the inside.

This is why I am not a fan of the center-lamp design. You just can't squeeze any more lumens out of a lamp. You are way better off going with 48" lamps, or just making 2 24" units. If you made a 4-4-4 unit, you would be better off making two 3-3 units, because you can reflect all the lights and maximize the power to the screen.

Also T5HO fixtures are 24" long, but the portion of the lamp that is actually illuminated is more like 20", so having much wider than a 22" screen doesn't do a whole lot. If you use T5HO waterproof endcaps, you end up with 19-7/8" exposed lamp.

Also like srusso said, you have a maximum lamp spacing of about 3 or maybe 4 inches. So 3 lamps on a side means a 12" x 22" screen, two of those means you have about 24x22 scrubbing power or about 525 gallons of filtering capacity. Having your lamp spacing a little wider than 3" will decrease that a little, but using T5HO you're ahead of the game, so that would effectively filter a 500 gallon fully stocked tank. So if you have 900 gallons and it's half stocked (or only moderately fed) that will probably work well.

Hope that helps

It is a lfs display fish system. I will have a total of 16 lights. 5 on outside, 6 in the middle and 5. The 5 on the outsides(or total of 10 outside) will have individual reflectors. The 6 in the middle will not have reflectors. I intend to space the screens as close to the lights as possible and still have splash guards.. If I could get 36" lamps I would but 48" is to long for this application.

[niqiri]

My scrubber is on a 90 gallon tank with about 450 gph running over it from the drain. I am using two clamp-on light fixtures with the bulbs I mentioned in the previous post, using the large, circular reflectors that came with the fixtures. I am sure the algae in the display is not cyano; it is a deep green color. I have tried feeding infrequently but the algae keeps growing. I have manipulated every factor since I put the screen in about a year ago, but nothing works. I do have faith in algae scrubbers, but it occurred to me recently that this was the only factor that I have not experimented with. I hope this clears things up.

[Floyd R Turbo]

Originally Posted by Robert Patterso

It is a lfs display fish system. I will have a total of 16 lights. 5 on outside, 6 in the middle and 5. The 5 on the outsides(or total of 10 outside) will have individual reflectors. The 6 in the middle will not have reflectors. I intend to space the screens as close to the lights as possible and still have splash guards.. If I could get 36" lamps I would but 48" is to long for this application.

I know, i read that post also. I'm tying to save you a little $ on lamps and fixtures. You will get the same amount of power if not more by doing 2 3-3 systems than you will a 5-6-5 system. The 6 lamps in the middle will be like 1/4 of a lamp each to each side. The remaining 1/2 of the lamp power is completely lost. So it will be like the equivalent of 1-1/2 lamps going each direction. Thus you have 2 screens with 6-1/2 lamp power, maybe 7 at the most.

If you're going to squeeze 5 lamps across 24", that's 4-5" per lamp. You're better off spacing 6 lamps 4 inches apart, 3 on each side, of a 12" tall 24" wide screen, and doing 2 of them. If you're dead set on a 24" tall screen (and you have the space to do that) then do them vertically and do 6 on one side and 6 on the other, and get good reflectors.

[Robert Patterso]

Originally Posted by Floyd R Turbo

I know, i read that post also. I'm tying to save you a little $ on lamps and fixtures. You will get the same amount of power if not more by doing 2 3-3 systems than you will a 5-6-5 system. The 6 lamps in the middle will be like 1/4 of a lamp each to each side. The remaining 1/2 of the lamp power is completely lost. So it will be like the equivalent of 1-1/2 lamps going each direction. Thus you have 2 screens with 6-1/2 lamp power, maybe 7 at the most.

If you're going to squeeze 5 lamps across 24", that's 4-5" per lamp. You're better off spacing 6 lamps 4 inches apart, 3 on each side, of a 12" tall 24" wide screen, and doing 2 of them. If you're dead set on a 24" tall screen (and you have the space to do that) then do them vertically and do 6 on one side and 6 on the other, and get good reflectors.

Ok sorry for asking dumb questions here. So your saying use 3 reflected lights per side for a total of 6 lights per screen, right? I am trying to cover the total gallons in the system that was why I was going with the 24x24 screens. We are wanting to make sure the scrubber will handle the load no matter what we throw at it. I will have a total of 16 lights, so should I put reflectors on all of them? Say 4 per side per screen?

[Robert Patterso]

By the way, heighth wise I have all the room I need. Probably 16 ft above the sump if that helps any.

[Floyd R Turbo]

Oh, in that case!!

So you want to do 2 sets of 24x24 screens, which would put you over 1000 gallons of capacity, right?

If that's the case, then 16 x 24W (24" T5HO) = 384 W and you're pretty underpowered. Realistically, you're probably not going to feed them 100 cubes of food a day though, are you? Because that's what a scrubber that size can technically handle.

That's why I'm thinking that your scrubber is a special case where you can undersize it, and make sure you have plenty of flow and light.

[Robert Patterso]

Oh no way will it ever see that much food, ever. But yes I am trying to cover right at 960 gallons. Of course the fish come and go, get sold. So the load is never the same. Up one day and down the next. We are trying to go to a more natural way of filtration. Each display tank is a 55 gallon tank except for 1 and its a 100 gal. I think. So while I am trying to filter that many gallons I don't think I have the room horizontially. The area I have to work with in the sump is 36x24. But I have all the vertical room I need. But from what I understand, and correct me if I'm wrong, horizontal works better than vertical. I've already ordered the bulbs so I am kinda stuck with it. I can always order more if need be, just need to come up with more end caps.

As far as flow goes, that's not a problem. The owner told me to grab whatever pump/pumps I need to get the flow I need

[Floyd R Turbo]

Are you going to do an enclosed acrylic box? I don't remember you mentioning anything except for lighting and screen dimensions.

[Robert Patterso]

Originally Posted by Floyd R Turbo

Are you going to do an enclosed acrylic box? I don't remember you mentioning anything except for lighting and screen dimensions.

No acrylic box, at least not right now. Goin to build a frame out of steel, all welded and powder coated. Once we get this up and running then we are going to plan and build one for the store's display sps/mixed reef. That one probably will be either acrylic or glass which will be on display right next to the tank itself. Hopefully to draw attention from the customers. Once we get the bugs worked out of the ones in the store we want to try and build and sell custom set ups to the customer. I believe this type of filtration system is the better way to go and cheaper in the long run. Don't need all the bells and whistles, skimmers and such. I will be building a better one for my personal tank here at home to hopefully take my skimmer and refugium off line.

[6Speed]

some more ideas I might work with. I like the idea of mounting some hangers to the inside glass of the sump. Heck I could even make some hangers that hang onto the top edge of the sump. Another idea I like, if I choose not to feed the thing from the overflow, is to utilize the return pump and a t-fitting plus valve.

The overflow idea I think is great bc 100% of the nutrient rich water will pass over the scrubber before going anywhere else. The con of that setup would be if the screen or pipe got clogged and the overflow wasn't able to deliver the same amount of water that the pump was sending into the tank. Then we'd have a big mess!

[srusso]

Originally Posted by Robert Patterso

...and correct me if I'm wrong, horizontal works better than vertical.

That is incorrect...

[srusso]

Originally Posted by 6Speed

The con of that setup would be if the screen or pipe got clogged and the overflow wasn't able to deliver the same amount of water that the pump was sending into the tank. Then we'd have a big mess!

Feeling like I have answered the question a million times, so if it sounds a little short thats why... but in short... A properly maintained scrubber can not clog on its own accord... The reasons have been posted on this thread a bunch of times. "In shorter" algae loses to the water pressure.

Nice single sided screen. Let us know how it works out for you. Thanks

[Floyd R Turbo]

Originally Posted by srusso

That is incorrect...

I think he was saying that a wider, shorter screen is better than a taller, narrower screen.

[Floyd R Turbo]

Originally Posted by 6Speed

I think that's a copy/paste of someone else's build, right? It was that guy that used to have that really long and narrow DIY acrylic tank that was totally awesome, then he sold it and made a Nano and this is his sump. Is that right? I think it was a TOTM at one point (the long tank)

[srusso]

Originally Posted by Floyd R Turbo

I think he was saying that a wider, shorter screen is better than a taller, narrower screen.

Yeah after reading the line a second time... you are right.

[6Speed]

Originally Posted by Floyd R Turbo

I think that's a copy/paste of someone else's build, right? It was that guy that used to have that really long and narrow DIY acrylic tank that was totally awesome, then he sold it and made a Nano and this is his sump. Is that right? I think it was a TOTM at one point (the long tank)

the pics I posted? yes those photos are from Calvin's thread in the nano forum. I really like his design.

edit: sorry, I see you quoted the pics too. I was reading the topic on my phone when I originally replied to your quote and for some reason the images didn't show up.

[6Speed]

Originally Posted by srusso

Feeling like I have answered the question a million times, so if it sounds a little short thats why... but in short... A properly maintained scrubber can not clog on its own accord... The reasons have been posted on this thread a bunch of times. "In shorter" algae loses to the water pressure.

Nice single sided screen. Let us know how it works out for you. Thanks

That's actually not mine. I was posting it bc I liked his design and wanted to incorporate some of the elements into mine.

Regarding clogging. You're telling me there is no chance that algae will grow on the screen close to where the screen meets the pipe? There is no chance of that algae growing thick enough to slow down the flow of the water as it exits the pipe?

I'm not concerned of algae growing in the pipe...just the stuff that may grow right up to the edge of the pipe.

I'm sorry if you've answered this before, but the thread is very long and I must have missed it.

[Floyd R Turbo]

I'm going to cover solution to this in detail in my Summary Part #2, but here's a sneak peek at my explanation of why it's not really a concern:

Slot pipe clog prevention

This issue is brought up on a pretty regular basis. Obviously, no one wants an overflow pipe to clog and overflow their tank. Most people take precautions to prevent livestock from entering the overflow pipe, such as an intake screen. In the case of the scrubber, they’re worried about the algae growing thick enough to stop flow at the point where the screen and pipe slot meet.

Almost without exception, this question is posed by someone who studies the design, but has never actually built or operated a scrubber for any length of time. I’m not trying to belittle anyone posing the question by saying that, rather just making the point that if you run a properly built scrubber, you’ll understand that this is really not a concern. Here’s why:

If you properly build and maintain a scrubber, there is virtually no chance that algae will grow thick enough to block the slot. I’m not saying that algae will not grow at the junction point of the slot and screen, it most certainly will to a certain extent. The water on the screen below the slot will get partially diverted over the top of the algae mat, as water takes the path of least resistance. As you approach the slot, the flow area is restricted to the narrow space between the pipe slot and the screen. This creates an area of flow pressure under which algae cannot grow to any significant thickness without succumbing to the pressure of the flow and releasing from the (smooth) screening material. Proper cleaning of the slot and the smooth portion of the screen during weekly screen cleanings virtually eliminates any chance of the slot clogging.

As for the interior of the overflow pipe and slot pipe, these can be clogged by variety of means. The most obvious of example is a snail, anemone, or other tank mate that makes its way down the pipe. This is a potential problem for any overflow pipe, but adding a slotted pipe with a cap on the end just makes some people nervous, because there’s no place for that obstruction to exit the overflow pipe. Fortunately, this is only a problem when you insert the screen too far into the slot pipe. If you only insert the screen far enough that is extends about 1/8” to ¼” above the inside of the pipe, then anything that makes it all the way through the plumbing to the slot pipe will get pushed to the end of the pipe by water pressure, and should only partially block the flow, and only at the end of the screen, if at all.

If you insert the screen all the way into the slot until it contacts the inside of the pipe, the obstruction could form at the beginning of the slot tube, and could substantially or completely block the water flow. However, this is perfectly fine as long as the inlet to your overflow pipe has a strainer on it that would prevent anything from entering the pipe.

I don't know if there is any advantage to full insertion vs. minimal insertion. Inserting the screen further into the slot pipe may even the flow out a bit, but I haven't noticed any glaring issues with the way I do it. This is why I recommend inserting the screen such that it protrudes no further than ¼” into the interior of the slot pipe.

With all that said, if you’re still concerned about the issue, and don’t want to take any chances at all (and you would be hard pressed to find someone to blame you), then there are a few techniques that can be implemented that will reduce or completely eliminate the chance of a blockage of the slot pipe causing your tank to overflow. Notice that I only mention a blockage of the slot pipe. This is because a blockage of the overflow plumbing before] the slot pipe is a totally different issue, but some of the solutions below will apply to both.

The 'few techniques' will be covered in part 2 summary.

I'll follow that with my personal note that after looking at hundreds of scrubber builds, threads, etc, I haven't seen one person say that algae grew into their slot tube clogged and overflowed their DT.

I'm not saying that it couldn't happen, but if it did, it would probably be directly attributable to the slot not being wide enough and pinching the screen, which would result in not enough flow from day one.