Algae Scrubber Basics

[Floyd R Turbo]

The the UAS, the concept is that bubbles 1) provide random flow 2) provide O2 and CO2 3) move the algae enough to allow light to penetrate to the lower layers.

The latter means you can theoretically go longer between cleanings. However you have a material between the screen and light (glass or acrylic) and this will grow a film of algae that needs to be cleaned also. I have noticed that with LEDs right against the glass, algae won't grow in front of them (making a little bare circle), so this may actually not be much of an issue. But at a minimum with a UAS it should be removed and rinsed weekly. Srusso I think he was just thinking out loud...not planning on monthly cleaning.

The die-off factor IMO is reduced with the UAS. I've let it go a full 2 weeks w/o even looking at the screen due to being too busy, and when I go to clean it, there are no signs of detachment. I'm not saying that it filters better, because that is IMO yet to be determined, but in my particular setup, detachment doesn't seem to be an issue.

As to the reflector issue, it will only matter for the first few days, then the algae growth on the screen will block the light passing through the screen.

 

[cpandrewschmidt]

Well, Got mine set up yesterday. Feed roughly two - two and half cubes a day. So, built a 4x6" screen, target 140 gph flow, lit from both sides. I'm running 23 w CFLs at 6 hrs on 6 hrs off for 12 hrs per day. Do my calculations seem correct? Should I run 12 hrs straight or split up? I wasn't clear on that.

Here are some pics! Hope this helps with my recent HA problem from switching to LEDs.

Andrew

 

[greg1786]

srusso....Floyd is right I was simply thinking out loud. I absolutely have time to devote to cleaning my screen regularly the reason it was the most inportant question for me was because until a few months ago....I had never had an algae problem.then I switched light and the new light is so wide, it actually overlaps my hob filters. this situation has caused gha to grow on the area where the water runs out of the filter back into the tank. This is essentially creating a waterfall algaescrubber right? so I was asking because I needed to knowfor myself whether the cause of my algae spread was because I had allowed it to grown in an area of high flow and light without cleaning regularly. and getting that answer to that question would be even more motivation for me to clean the screen regularly


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[srusso]

srusso....Floyd is right I was simply thinking out loud. I absolutely have time to devote to cleaning my screen regularly the reason it was the most inportant question for me was because until a few months ago....I had never had an algae problem.then I switched light and the new light is so wide, it actually overlaps my hob filters. this situation has caused gha to grow on the area where the water runs out of the filter back into the tank. This is essentially creating a waterfall algaescrubber right? so I was asking because I needed to knowfor myself whether the cause of my algae spread was because I had allowed it to grown in an area of high flow and light without cleaning regularly. and getting that answer to that question would be even more motivation for me to clean the screen regularly


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I apologize for the misunderstanding. No the algae that is growing on your HOB is not creating the algae issue in your tank.

Nutrients found in the water column are aiding your unwanted growth.

 

[greg1786]

no worries I am actually thrilled to have you respond to my post because your the sole reason why I'm doing this I was browsing Google for a solution to my algae issue that I hadn't uet tried( which was just about everything w no luck) when I came across a site where you had diagrammed this UAS design and were kinda getting mixed responses and even a few who were slamming the idea and sayin you were "spamming " their forums. well I just want to say thank you so much for pushing the idea even when ppl were so skeptical. I just got my scrubber built and finally in the tank at 4am! thanks for everyone's help and any more advice or ideas for a betrer build for me are greatly appreciated. id really like to build a turf scrubber eventually!!!!


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[greg1786]

my appologies for the incorrect info in my last post. I was under the impression that you were Santa Monica which is not correct. still however thanks for everything yoyve done to promote his wonderful idea


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[srusso]

my appologies for the incorrect info in my last post. I was under the impression that you were Santa Monica which is not correct. still however thanks for everything yoyve done to promote his wonderful idea


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LOL no problem, thank you.

 

[LiMaZoo]

I can't find where it was mentioned earlier, but does anyone know a decent online place where I could place orders for cut acrilic? or better yet, would glue it for me if I give them the specs?

 

[JohnnyB in SD]

Thats great, thanks for helping flesh out this new theory.

(Blahblahblah - edited)

In my own tests I have noticed a drop in phosphates as I predicted, from 0.14 down to 0.01 on a Hana checker. The only other tester to post findings so far has reported that it hasn't help fix the phosphate issues. So it's one and one right now.

As others test, I believe we will see this fixing rising phosphates for some and others may actually have a different or multiple limitations.

I picked up a KorallenZucht test kit last night from a local reefer. I would say it's coming up 225ppm, definitely well under 300ppm. Difficult to read ridiculously subtle shades of color on the low end of chart.

My N is about 10ppm, and P came up 0.05 on a Hanna last night. About half of where they were a week ago. I'd say the levels had crept up so high because the DT requires more effective flow. There is a lot of detritus accumulated in and on the rockwork, which I am occasionally target blasting to remove as a short term solution. $1k for some Vortechs is only in my dreams at this time.

I feed an average of 16-18 cubes / day. Running two scrubbers with a total of 250 sqin effective screen area. One is CFL, the other LED. Decent harvests, still tweaking things to improve towards more green from brown.
I'm going to begin slowly dosing K levels up starting tonite. We'll see if this Primary Production theory has any influence on the scrubbers. In any case, the tank needs more K anyway.

 

[Floyd R Turbo]

Johnny, thanks for the feedback on the KZ test kit. I was told by someone with a lot of experience that the Elos test kit is the most accurate one, all the others are probably only good for tracking trends, so you can tell if the level went up or down within reason, but you really don't have a solid base point of reference to start from I guess.

 

[caribfan]

Hello,

I am new to reefcentral and completely new to the idea of ATS, but it sounds like it could be the answer to my problems. I have a 120 gallon FOWLR that consistently has nitrates in the 60 - 80 ppm range. I have tried a RDSB and not had any success. I'm currently doing 25 percent water changes on a weekly basis.

I'm planning to make an in sump version. I am going to use a 15" x 15" screen. Is this as simple as roughing up the screen, cutting a slot in a piece of PVC pipe and having the appropriate flow across the screen?

Is there a recommended way to cut the slot? How important is the width of the slot? It looks like there is an overflow outlet at the end of the manifold, is this correct? I am going to start on this project this weekend, im really excited to see how this impacts my tank.

I'll try to post some pics of my build when I'm finished.

 

[silverwolf72]

Don't know if this really belongs here. I've noticed that every K measurement I seen posted is in the 220ppm range, makes me think there is something going on in our tanks that makes K want to stabilize at that level.

 

[JohnnyB in SD]

FRT -
Yeah, I don't expect laboratory accuracy. For the price & quick availability it will work as a starter, but it does suck. Is like trying to read Phosphate on those light blue Salifert cards. At least I'm confident that I'm not dosing something that's already too high.
Heck, Steve doesn't have a clue what his level is, so maybe it could be worse.
If this theory merits deeper investigation, I'll get an Elos & try to correlate the KZ numbers to it somehow.

 

[srusso]

I picked up a KorallenZucht test kit last night from a local reefer. I would say it's coming up 225ppm, definitely well under 300ppm. Difficult to read ridiculously subtle shades of color on the low end of chart.

My N is about 10ppm, and P came up 0.05 on a Hanna last night. About half of where they were a week ago. I'd say the levels had crept up so high because the DT requires more effective flow. There is a lot of detritus accumulated in and on the rockwork, which I am occasionally target blasting to remove as a short term solution. $1k for some Vortechs is only in my dreams at this time.

I feed an average of 16-18 cubes / day. Running two scrubbers with a total of 250 sqin effective screen area. One is CFL, the other LED. Decent harvests, still tweaking things to improve towards more green from brown.
I'm going to begin slowly dosing K levels up starting tonite. We'll see if this Primary Production theory has any influence on the scrubbers. In any case, the tank needs more K anyway.

Thank you for posting this! Cant wait to hear an update. Please let me know when you start dosing! With Potassium levels that low I am really starting to have a lot more confidence in my theory.

Thanks again Johnny!!

 

[srusso]

Johnny, thanks for the feedback on the KZ test kit. I was told by someone with a lot of experience that the Elos test kit is the most accurate one, all the others are probably only good for tracking trends, so you can tell if the level went up or down within reason, but you really don't have a solid base point of reference to start from I guess.

I am sure the test kit can tell us that his like I believe most algae scrubbed tanks are actually potassium limited. Maybe the number isn't dead on but it is saying you are way low!

It should be about 400ppm, big difference from 225, or 300 for that matter.

 

[srusso]

Hello,

I am new to reefcentral and completely new to the idea of ATS, but it sounds like it could be the answer to my problems. I have a 120 gallon FOWLR that consistently has nitrates in the 60 - 80 ppm range. I have tried a RDSB and not had any success. I'm currently doing 25 percent water changes on a weekly basis.

I'm planning to make an in sump version. I am going to use a 15" x 15" screen. Is this as simple as roughing up the screen, cutting a slot in a piece of PVC pipe and having the appropriate flow across the screen?

Is there a recommended way to cut the slot? How important is the width of the slot? It looks like there is an overflow outlet at the end of the manifold, is this correct? I am going to start on this project this weekend, im really excited to see how this impacts my tank.

I'll try to post some pics of my build when I'm finished.

Scrubbers work very well on fish only tanks... Say good by the all those waters changes! 25% a week holy cow!

Can't wait to see it! Please do share, and welcome to the scrubber club!

 

[srusso]

Don't know if this really belongs here. I've noticed that every K measurement I seen posted is in the 220ppm range, makes me think there is something going on in our tanks that makes K want to stabilize at that level.

Stabilize isn't the word I would use, it is actually the limitation of the potassium in its relation to the other nutrients that would make it stay about that level.

 

[caribfan]

A couple questions about the build.

How is the screen held in place? Should it just be jammed up into the PVC "manifold", or is it suspended just below the slit?

Am I correct in that there should be an overflow at the end of the manifold back into the tank?

What is the best way people have found to cut the slots in the PVC? Does it have to be 1/8" exactly?

I know this thread is for the basics of how they work, is there a build thread anywhere that goes into the construction of these things?

Thanks in advance, i'm really looking forward to cutting back on my water changes, or at least having some control over my Nitrates.

 

[srusso]

A couple questions about the build.

How is the screen held in place? Should it just be jammed up into the PVC "manifold", or is it suspended just below the slit?

Am I correct in that there should be an overflow at the end of the manifold back into the tank?

What is the best way people have found to cut the slots in the PVC? Does it have to be 1/8" exactly?

I know this thread is for the basics of how they work, is there a build thread anywhere that goes into the construction of these things?

Thanks in advance, i'm really looking forward to cutting back on my water changes, or at least having some control over my Nitrates.

In my opinion, no method for hanging the screen is better then the DIY PVC rings.

Using a coupler or T fitting for the same size PVC you are using for the slot tube.

So if you are using 1" PVC, get a 1" coupler.

Cut a ring off the end of each side of the coupler, about 1/2" thick. Take these PVC rings you just made and cut a notch from each, making them look a "C"

Slide these two rings over slot tube before you glue the end cap on.

Cut two 1/2" holes in the top of the screen, for the rings to hook through.

When inserting the screen rotate the rings to the point the notch in the rings you made line up with slot tube and the holes of your screen. Turn the ring on each side to keep it in place. Turn the ring again to remove.

This has the following improvements of zip ties:

Last the life of the scrubber.

No buying new zip ties.

No cutting zips

No zipping new ties, with wet hands (really sucks)

No over or under tightening the zip ties!
That's a big one!

So the screen sits in the same place each time, same dept into the slot, etc..

The screen also hangs freely, so it gives/moves slighting when needed for changes in flow or growth...

Mostly it's so much faster to takeout and re-hang!

As for the slot the cleaner and straighter the cut is the better. Yes 1/8" of an inch.

Screen should be inserted into the slot, that's why the width of the slot is important.

No need to make an over flow on the end of the slot tube, if your getting that from old pictures of my design from testing different things. It isn't needed at all.

Check my or Floyd's signature for build details.

 

[Floyd R Turbo]

On the Low Potassium issue, I was told that if my K was indeed 325 as the Salifert kit showed (there is a dramatic color change with this kit, there is no color card) then he said that was "very low, and you should correct it". NSW is 390-410 (his words) and you need to keep it in that range. He also mentioned that one primary indicator of K deficiency is Red Monti Cap, if it looks faded or washed out, your K is low, otherwise, It's probably not. So I guess I will get the Elos kit, then adjust K as necessary, and watch the color of the Montis, and if they change to a more vibrant color, I'll know they were previously washed out! I never really paid attention before.

But to those of you testing K <250, I would say that on any test kit, that's low.

W/R to test kits in general, he said that most are accurate to the level that we care about, with some brands being better than others. K in particular was probably the least reliable accurate of them all, with Elos being the best one.