Algae Scrubber Basics

[sensei]

Floyd,

the rough section of a canvas I just made is 11 x 9"
I measured the flow of water and it is 768GPH.
I read that the flow should be 35GPH per inch.
in my case 11 x 9 = 99 inches *35 GPH =3,465 GPH; but it seems to much flow.
please let me know the correct flow I should have with this canvas.

2.- I am a little confused if a Algae scrubber can over scrub nutrients or not.
You mentioned that one of your aquariums show a NO3 level of 0, so I guess the ATS is pulling all the N from the water. In this sense I guess you can say it can over scrub, and what one could do is lower the light period if you want N levels to show in the water??

waiting for your answer

 

[Floyd R Turbo]

You only care about the width (slot pipe length), the area (LxW) calc is only for capacity. Otherwise your calculation would be 35 GPH per square inch, not per inch (lineal)

IMO you can't really over-scrub, but I suppose that is up for debate and depends on what your goal levels are. But, a scrubber that is too large might end up not growing very well because the algae growth will spread out too thin. That doesn't mean it won't work, it just might not be the most efficient that it could be.

If you are feeding the tank on a regular basis, you will always have some nutrients in the water column. Nutrients are usually still present at what is considered ULN levels.

If you wanted to keep N and P at a slightly elevated level, you would just adjust the photoperiod, intensity, flow, etc. But that would take some experimenting

 

[sensei]

Thanks for your answer Floyd,

if the slot pipe length is 10" then the correct flow should be 10*35 =350GPH correct?
what happens if I leave have a higher flow? lets say double that flow?

thanks again

 

[Floyd R Turbo]

Correct, that is the rough target flow you are shooting for (actual flow coming off the bottom of the screen)

You can start out lower, sometimes this is better to encourage algae to initially attach. However that may not matter if you use the mortar screen method, new stuff, new things to learn...

As far as higher flow, I guess it depends on the need. I would start out with the standard flow. Once you get a mature screen that you need to scrape on a regular basis, if that isn't filtering well enough for you, then you can increase the flow and try to get more production out of it. Usually you will want to also increase the light intensity and/or photoperiod when you increase flow.

There is a point of diminishing returns though and it seems that if you go too much over about 50 GPH/in, it doesn't do a whole lot more good. So there's no need to do super crazy flow, for most cases

 

[herring_fish]

A Kooky Way

A Kooky Way

I used the mortar and it worked great. I am just guessing but what we would call algae roots must work their way into the plastic much like other plants can work their way into sidewalks, starting with a foothold in small cracks and forcing them open into large ones. Since plastic is so non-porous, this process can take a long time.

If that is at all plausible, that would explain why getting active growth in mortar in close proximity on the plastic can jump start the process.
I know that after several years of operation my horizontal dump bucket scrubber, with the screen lying on the bottom of the tray, the smooth acrylic started growing algae so that I could discard the screen. I don't believe that removing and replacing the screen scratched it up and I never scraped the tray. I just grabbed hands full of algae and threw them away. It still looks clear and scratch free. When I took it out of service for quite a while and re-started it, the algae took a shorter time to get a foot hold but it did not start right away.

Another theory is that the light and age caused micro cracks in the surface and the algae attached to that.

Anyway back to the screen. I bought a cheap wire brush attachment for my electric drill. You know, the type you might buy to clean rust off of something or to power scrub a grill. I used that to rough up the screen as the final step instead of the saw blade. The brush cost about the same as the saw blade but the results are about the same. It's just another way to do it.

Now this might be a waste of time but I had left over sand paper from a wood finishing project so I put it to use. I started off the roughing process by sanding the screen with fine sand paper and then going rougher and rougher until I was using the coarsest grit. Only then did I use the power drill. This is the opposite from how you would sand a piece of wood before finishing it.

What I wanted to do was to add those super small scratches in the plastic and then bigger ones and so on. Of course if I did it the normal way, the roughed plastic would be sanded back smooth but this way the hair like burs would hopefully have secondary cuts in them, with tertiary cuts in them, like a feather has branches on branches, (repeat). It seemed like it came out just a little fuzzier that way.

 

[Floyd R Turbo]

I use this

or this

Just a couple $ at Lowes for either one.

Using these with the drill at a relatively low speed (maybe 150-300 RPM I would estimate) with a little pressure takes the "shine" off the entire surface of the screen, deep into the holes.

What I do is clamp the screen down to a piece of MDF that is clamped down to a work surface, so it doesn't roll up while using the drill/bit.

IMO using sandpaper does rough up but it also removes material off the surface while not roughing up inside the holes/squares.

Using a sharp saw blade like this 12pt 10" one (the big one)

is what I am using in the video, and while this does remove quite a bit of material, it tears the screen up and leaves it 'prickly' while sanding generally does not.

So my plan is to use the wire brush drill bit attachment as I have been doing, then do a much quicker rough-up (maybe take 1/4 of the time I used to) and then do the mortar.

Over time, what I have seen is that no matter how prickly you make the screen initially, it seems to lose that prickliness eventually. However this does not seem to affect the screen ability to grow algae, so that's why I have theorized that the plastic will eventually be encrusted with a layer of calcification, not dissimilar to what you can see on a glass tank over time - that limescale that is really difficult to remove.

It's probably the same type of deposit that you get on smooth acrylic - an almost imperceptible layer of scale or calcification that has just enough microscopic roughness such that algae will easily attach to it and grow. You can dry it out and it will remain as a 'skeleton' upon which the algae can quickly attach.

This take time to form but once it's there, you would probably have to use acid or vinegar to remove it. That's why a 'dead' screen (like one left with no flow) will grow back quickly.

 

[C Dog]

Are there websites that sell premade kits?

 

[sensei]

Floyd,
can I know which pump is the one that you recommend for L4 Algae scrubber from Turbo's Aquatics, LLC??

If tell me the specific brand and model, it would be better.
Thanks

 

[Floyd R Turbo]

For a 12" wide screen that is about a foot above the waterline, you want 400-450 GPH after head loss (which ends up being about 36" total). For that a Rio 1700 is a pretty good match

 

[sensei]

Floyd,
I think the screen of the L4 algae scrubber REV 4 from Turbo's Aquatics is smaller
can you tell me what size is it?
would the same rio pump work fine or a smaller one for that scrubber?

 

[sensei]

I will be cycling my new 470g DT soon. I will seed that tank with bacteria loaded ceramic rings and add bacteria solution in a bottle. I have read that cycle should be completed in around 3 days. after that I will be adding fish slowly.
questions :
when should I install the algae scrubber??
should I put it in the sump since day 1?
I ask because at the begining there will not be much nutrients in water and I dont know if it good or not to start cycling a tank with an ATS installed??
I guess I should dose some food since day 1 to feed the bacteria and kick the cycle??

Yes, it won't hurt anything to start it on day 1, but like you said, you just might not get a lot of growth. You will likely get a brown diatom coating, and the screen will start to get some calcification, so these are good initial stages that you would have to go through anyways, so the earlier, the better. Then, when you start to add some livestock and get some biodiversity going, the screen will start to react a little more quickly, vs if you waiting until you have some nutrients and then start the process.

You can always use a short photoperiod and a lower flow rate to start up the screen. So maybe 50-75 of the flow you would normally run it at, and then just a few hours/day of light.

Floyd,
above you say that it is better to start the scrubber from day 1 in a new DT, I am just a little worried that if I run it from day 1, the scrubber will consume most available N and P from water, so to lower the capacity of scrubber I could run it from day 1 at a flow of 20GPH / inch and only light the screen 6 hours??

do you think this is a good idea? please tell me what you think

how much time does a new ATS needs to be running to go through the initial steps and be ready to work at full capacity?

can I know which are the initial steps that the ATS has to go through?

Thanks

 

[karimwassef]

Ok. Set up my "end to end weir overflow scrubber"

I didn't realize this stuff floats. I let it float but we'll see if that's the best solution.

It's 5" wide x 5' long. I zip tied 5 sheets that I roughed up with a hole saw drill bit. I used pex tube to get smaller than a 1/2" PVC.

<a href="http://s1062.photobucket.com/user/karimwassef/media/11255F3A-5F0C-4257-87B0-07F1E302D3D0_zps2ctw7vsf.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/11255F3A-5F0C-4257-87B0-07F1E302D3D0_zps2ctw7vsf.jpg" border="0" alt=" photo 11255F3A-5F0C-4257-87B0-07F1E302D3D0_zps2ctw7vsf.jpg"/></a>

Here's the view of the whole thing submerged/floating. The three halides are overhead provide a lot of direct light.
<a href="http://s1062.photobucket.com/user/karimwassef/media/57760BBB-8F72-4197-A829-400A6AB62587_zps7vikutzx.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/57760BBB-8F72-4197-A829-400A6AB62587_zps7vikutzx.jpg" border="0" alt=" photo 57760BBB-8F72-4197-A829-400A6AB62587_zps7vikutzx.jpg"/></a>

Left side
<a href="http://s1062.photobucket.com/user/karimwassef/media/89A4177E-53E3-4A3B-A3DF-4F3C81F78603_zpsyxtc5vsb.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/89A4177E-53E3-4A3B-A3DF-4F3C81F78603_zpsyxtc5vsb.jpg" border="0" alt=" photo 89A4177E-53E3-4A3B-A3DF-4F3C81F78603_zpsyxtc5vsb.jpg"/></a>

<a href="http://s1062.photobucket.com/user/karimwassef/media/1D098F5C-3189-4824-BC61-F529CD34CC34_zpspvekk9w2.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/1D098F5C-3189-4824-BC61-F529CD34CC34_zpspvekk9w2.jpg" border="0" alt=" photo 1D098F5C-3189-4824-BC61-F529CD34CC34_zpspvekk9w2.jpg"/></a>

Right side
<a href="http://s1062.photobucket.com/user/karimwassef/media/1D66E21F-582D-4998-907B-873009F9C68B_zpsx09lneve.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/1D66E21F-582D-4998-907B-873009F9C68B_zpsx09lneve.jpg" border="0" alt=" photo 1D66E21F-582D-4998-907B-873009F9C68B_zpsx09lneve.jpg"/></a>

<a href="http://s1062.photobucket.com/user/karimwassef/media/18500614-0EB5-40B0-8A17-FE3D9E03585D_zpsigzkjecw.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/18500614-0EB5-40B0-8A17-FE3D9E03585D_zpsigzkjecw.jpg" border="0" alt=" photo 18500614-0EB5-40B0-8A17-FE3D9E03585D_zpsigzkjecw.jpg"/></a>

Top views:
Left
<a href="http://s1062.photobucket.com/user/karimwassef/media/39A6FF73-F777-42B3-BE95-FDD0EA49E873_zpsgtg04ray.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/39A6FF73-F777-42B3-BE95-FDD0EA49E873_zpsgtg04ray.jpg" border="0" alt=" photo 39A6FF73-F777-42B3-BE95-FDD0EA49E873_zpsgtg04ray.jpg"/></a>

Right
<a href="http://s1062.photobucket.com/user/karimwassef/media/C17D90A8-14AB-4102-A754-A111B52E3C19_zpsjw1gh96l.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/C17D90A8-14AB-4102-A754-A111B52E3C19_zpsjw1gh96l.jpg" border="0" alt=" photo C17D90A8-14AB-4102-A754-A111B52E3C19_zpsjw1gh96l.jpg"/></a>

Cleaning up the section here was a bit of mess. Lots of coralline, hair algae, snails, crabs, pods, starfish, even anemonae.

We'll call today day 1 of the weir scrubber experiment. Flow varies from steady state 4000gph to a surge variance between 2000gph and 8000gph. Not all that flow moves over the sheet since only 5' out of the total 8' is covered. But it experiences flow in two directions: once in the overflow direction and another from left to right since the main overflow pipe is on the far right, so all the flow from the rest of the weir has to cross to get to the right.

 

[salty joe]

I predict you have a winner! And no additional energy cost is sweet.

 

[Floyd R Turbo]

Karimwassef, look back at post 7106

 

[karimwassef]

I like the mortar idea for accelerating getting the scrubber online. I only have narrow windows of time to get some of these projects done before I need to travel or address other responsibilities, and I'm ok waiting for the algae to take hold gradually.

Haha- just realized that I said "I have more patience than I have time". Don't even have a word for that? Not really irony?

 

[karimwassef]

The mortar should make it sink too. I'll see if this works. If not, I'll mortar it.

 

[james30ct]

I have a 180g mixed reef with 3 tangs. I bought a 200gph pump and have it on a 12x10" screen. Im going to do 27k cfls at first and may change to leds. Should I light bith sides of the screen?

 

[Floyd R Turbo]

Is 200GPH what you meant or is that a typo?

You need actual flow (after head loss) closer to 35 GPH per inch of screen width, so if you have it on a 10" wide screen, 350 GPH with about 36" of head.

You're looking at something more like 500 or 600 GPH at zero head in order to get 350 across the screen.

I would light both sides of the screen, but the first thing I would review is the screen size, 10x12 is big enough (when lit properly) for 10 cubes/day of feeding. If your lights are smaller than what they would need to be for the screen size, then you can reduce the screen size to match the lighting (and that might reduce your flow requirement a bit)

 

[SantaMonica]

So what kind of algae is this growing on the scrubbers?

Once it grows green, it's usually Cladophora, and if it growing fast it's usually Ulva Fasciata, sometimes with with Ulva Lactuca.

Also, is there anyone who ran a fuge with macro algae at one time & a scrubber at another & what was the outcome?

Many people have added a scrubber to a fuge, and the fuge macros died. After all, the scrubber thinks the macros are nuisance algae, and the stronger photosynthesis of the scrubber out-pulls the nutrients away from the macros.

Abusive methods? Can you link some?

Things like overdosed iron, and copper wires.

I'm intrigued by the mechanism by which the scrubber is providing pods and food for tangs

Simple: algae is what pods eat. And algae and pods are what tangs eat.

if a Algae scrubber can over scrub nutrients or not

No, because as nutrients get low, the scrubber slows down.

what we would call algae roots must work their way into the plastic

I think what it really does is wrap around the open grids of the screen.

What I wanted to do was to add those super small scratches in the plastic and then bigger ones and so on

This is good, just a lot of work.

Are there websites that sell premade kits?

No, it's almost the same as reading these forums and getting the parts yoursef.

can I know which are the initial steps that the ATS has to go through?

Usually slime to start, then green hair. Then maybe some corelline or lime buildup, which you can scrape off.

I didn't realize this stuff floats

Yes most screen is polypropylene, which is like the rope they use for skiing.

 

[salty joe]

Yes most screen is polypropylene, which is like the rope they use for skiing.

While polypropylene is outstanding for water immersion, it does not hold up well to UV at all. I used some for a critter guard and it got crispy in a couple three months. It was exposed to the sunlight through commercial skylights that claimed to block UV. So, if your lamps are putting out any UV, don't expect the poly to last.