Algae Scrubber Basics

[Floyd R Turbo]

I clean the slot. Run my fingers up/down the sides and pull any excess off. I'll give it one more good rub.


Corey

An additional note, I always use a brush to scrub out the slot to make sure it's clear, and then I use a scraper or my thumbnail and run it along the inside and outside edges of al the light blockers, then scrub them with a stiff brush. I do this every harvest or about every 10-14 days.

Also make sure you are scrubbing the top 1" of the screen with a stiff brush (I use a grout & tile brush) to make sure there is no growth forming.

I don't think either of these are the cause of your issue. It might be a stage in the re-start of the screen, hard to say. Keep us posted

 

[LQT]

Just did a quick check on the progress of my Turbo’s Aquatics L2 Rev4 ATS. It has been running for about 4 weeks now. It’s running on a brand new tank and the screen has been sitting in my rock curing tub for a few months prior to setting up the scrubber. I have it at about 25% intensity with the potentiometer dimming knob at the 6 o’clock position, running for about 9 hours a day opposite of my DT lights. I was expecting the slime growth stage, common with most ATS screen break in periods. To my surprise, I have a nice and even layer of firmly attached hair algae developing on the screen. I may look into either upping the intensity or increasing the photoperiod to get some faster growth now that the screen seems to have broken in properly. Very impressed with the performance of this ATS thus far... Thanks Bud!

 

[Floyd R Turbo]

Yup, I would add a bit of intensity - maybe a 1/8 turn - and then extend hours. Being a new tank, you'll want to go slow on intensity, but you can run very long hours at low intensity.

You can add a few hours to the daily photocycle of the scrubber with each harvest. Watch growth and take pics so you have a record and don't have to guess and recalling what it looked like.

Intensity is "instantaneous". If you don't have nutrients being supplied, cranking intensity can cause photosaturation. But if you get good growth at a given intensity, adding hours won't cause photosaturation (unless nutrients get really low and you curtail feeding significantly, etc).

As for cleaning, you don't have much to clean off per that pic, so I wouldn't do much. No scraping, no brushing, just rub & rinse with fingertips while running under tap water.

Scrub top edge and slot pipe of course

 

[LQT]

Thanks Bud. I just checked the screen, took a picture and put it back online. I’ll go 1/8th of a turn and leave her be. I’ll take a shot of the screen in a couple of weeks.

 

[wildman926]

An additional note, I always use a brush to scrub out the slot to make sure it's clear, and then I use a scraper or my thumbnail and run it along the inside and outside edges of al the light blockers, then scrub them with a stiff brush. I do this every harvest or about every 10-14 days.

Also make sure you are scrubbing the top 1" of the screen with a stiff brush (I use a grout & tile brush) to make sure there is no growth forming.

I do this with every cleaning. It makes sure you are growing algae for as much and long as possible between cleanings.

 

[HarrisonMG]

Finally finished! Here's my algae scrubber that I built for my 75g tank, after weeks of planning.
<iframe src="https://drive.google.com/file/d/1RIyU-aTcu7eDUtBkQI3jvzhbO12sqajP/preview" width="640" height="480"></iframe>
<iframe src="https://drive.google.com/file/d/16ouNMKd_k6PXQN1QszwnXFfn2UIMtK0j/preview" width="640" height="480"></iframe>
<iframe src="https://drive.google.com/file/d/1NCKJI7pMiJqxTGGB7pGP7HkJoNuVqksr/preview" width="640" height="480"></iframe>
<iframe src="https://drive.google.com/file/d/11W2YYxLg8Fabh5puYTYL-FlvrXa85O3s/preview" width="640" height="480"></iframe>

I realized that because of my sump setup, I could not have the unit just sit on top of the sump -- there is simply no space. It would've had to have gone in the return section, and then everything in there would be cramped, and the light on the outside of the sump would have been in my way....I could go on. I realized the best would be for it to go on the empty wall opposite the end of my sump. I also knew I'd have to design things from the ground up, to maximize the plastic sheet space, minimize noise, light leak, and space used by the unit. That's how I ended up mounting it the the side of the stand and draining with a bean animal system.

This is my sump before and after:
<iframe src="https://drive.google.com/file/d/1k2umRWao02L85L0lZjcndDwBgpBte6us/preview" width="640" height="480"></iframe>
<iframe src="https://drive.google.com/file/d/1cr3ycZ8J3nIQ80DBv00aKDSdwJ7Cw-UV/preview" width="640" height="480"></iframe>

The box is made of ¼" acrylic, but I made a prototype in 1/8". The prototype, I cut out on the circular saw and was displeased with the edges. For the real deal, I went to my local library, which got a new handheld CNC machine, the Shaper Origin, and boy was that cool! Anyways, I ran into many challenges along the way.
For one, I couldn't get the slot pipe to be even flow, so I ended up stacking 4 cutoff bits on my Dremel for the desired width of the slot, instead of going around the edges.
The light I got (it was the exact same cost as making one DIY, but came with a casing and a fan) is the exact width and height of the scrubber, but I had no way to suspend it, so as you can see in the photo, I built a stand. The surface actually pops off so it can come out, and the distance from the acrylic to the union I calculated to keep the stand rock solid.
To combat light leak, I cut out some cardboard fit to the sides of the scrubber, one side covered in aluminum foil and the other in navy duct tape. It works for now, I guess. The front piece is only taped up on one side so it swings open for easy look at algae.
Finally, I wanted the pipes as out-of-the-way as possible, so you can see the drains come out and then go to the sump at a 45 degree angle so they aren't right up front, but what you don't see is that the input pipe goes up from the sump against the front of the stand, over the door opening, and then connects to the spray bar w/a union.

Here's my tank:
<iframe src="https://drive.google.com/file/d/133UZ4VvlQ6ok7GVkZvVjjOhR1iBPouaA/preview" width="640" height="480"></iframe>

I'll update in a few weeks when algae comes in, but so far....thoughts?

Thanks!
--Harrison

 

[hkgar]

Finally finished! Here's my algae scrubber that I built for my 75g tank, after weeks of planning.
Thanks!
--Harrison

How large is that screen?

 

[HarrisonMG]

How large is that screen?

It is an 8.5x11 and about 1.5 in are blocked by the shield

 

[SantaMonica]

Might need to dim or shade it to start, since it probably is very strong. Check the case ground pin too for safety. Then see how it grows as-is.

Easy performance mod is to simulate 2-sided by placing a white plastic sheet behind the screen, and cut some tall diamond-shaped cutouts in the screen so light can get through and reflect back to the other side.

Best mod is to get a light on the other side. 2-sided is always far better than 1-sided, for waterfalls, because of the mat-down. This does not happen as much in upflows.

But just see how it does now.

 

[HarrisonMG]

Might need to dim or shade it to start, since it probably is very strong. Check the case ground pin too for safety. Then see how it grows as-is.

Easy performance mod is to simulate 2-sided by placing a white plastic sheet behind the screen, and cut some tall diamond-shaped cutouts in the screen so light can get through and reflect back to the other side.

Best mod is to get a light on the other side. 2-sided is always far better than 1-sided, for waterfalls, because of the mat-down. This does not happen as much in upflows.

But just see how it does now.

Yeah I was worried, once I turned it on, that it was so bright. I made the reflectors to try to bring light to the other side but won't be able to install the one on the back till I clean the screen and remove the scrubber.

I don't feed that much, so I guess I figured the nice large screen could compensate but to be honest I never did the math........

In the future if needed I guess I could add those waterproof strip LEDs to the inside although they may have to go in at an angle. It simply wasn't ideal to have a light on the other side for space, cost, and ease of access reasons.

Will the algae just not grow if it is too bright? I could find something to put in front of it I guess.

Thanks!

 

[hkgar]

I don't feed that much, so I guess I figured the nice large screen could compensate but to be honest I never did the math........



Thanks!

Here is the size calculator

 

[SantaMonica]

The algae will not grow if too bright. A little too bright in the middle is ok, and will create growth rings which are fine to start out. But that big light might blank out the whole screen, so shading half of it with a black cloth or something would help.

 

[HarrisonMG]

Here is the size calculator

Oh that is so cool! Thanks for sharing! I seem to have hit the mark on pretty much every one of the recommendations, save for that my screen is taller than need be and my pump might be a little underpowered (200ish gph). Still the flow coming out is very good, when I lower the shield it distributes the water evenly across, too.

Thing is, these calculators make me feel like maybe I'm not feeding my fish enough!? I put 2 or 3 cubes in a bottle, and it used to last me almost a week and now I feed it twice a day (as opposed to pellets the other time) which takes about 4 days to finish. That's like an avg of only ¾ a cube a day for all my fish. Maybe the seaweed makes up for it? Hmmm

And for the light, what about just putting a piece of paper in front? That will diffuse and dim

Thanks! --Harrison

 

[Floyd R Turbo]

It's really the other way around - you should size the screen according to your bioload, which is primarily related to how much you feed.

It appears that you might have used the previous guideline, which was based on tank volume? But I think you are running one-sided, so that's a factor.

8.5x11, less the 1.5", 7x11 = 77 sq in, at 12 sq in/cube/day that's over 6 cubes/day capacity, then cut that in half (or more) for single sided, you're at 3 cubes/day. So maybe not that far off, but the point being that if you feed 2-3 cubes/day, you could have built a screen with an active growth area of 36 sq in and light it on both sides - would take up less room and you wouldn't need as much flow (smaller pump, less heat, less power, etc)

I'm in agreement that the light is maybe a bit much, at least initially. You may get bald spots in front of the LEDs, or if they are overall just too intense, the entire center of the screen will be bare and it will get growth around the edges - but should eventually fill in (might take a while).

As for flow, your max flow should be 35 GPH/in of screen width. You can start out with a lot less, as the initial break-in period doesn't really require a ton of flow. You could drop it down to 25 GPH/in or maybe less - the thing to do is just adjust the flow so that you get coverage on most of the screen without arcing (too much) or leaving the far end dry (too little).

Back to the light - intensity is good, if you have the nutrients to support it and the algae growth is mature. Initially, high intensity is growth-prohibitive. In order to knock down the intensity, you first have to consider the fixture and what it prevents you from doing.

In this case, I'm willing to bet that the front panel of the fixture is glass, and it gets hot after it's been running for a few hours. So I would not use any type of cloth that gets into direct contact with the fixture, and I would not attach anything to the front of the fixture or the glass. No tape, no diffuser, etc.

What I would instead do is one of the following:

1) get a piece of diffuser from Home Depot/Lowes/etc and cut it to match the footprint of the light, then attach that to the clear scrubber panel. This stuff is like what is in a 2'x4' recessed ceiling grid light fixture. It is smooth on one side, and bumpy on the other. Cut carefully as it shatters, it's best to use a razor knife and make multiple passes before snapping it (and wear eye protection, and use gloves...trust me on this!)

2) if you use a cloth, attach to the scrubber clear acrylic.

3) add pieces of blue painters tape on the scrubber clear acrylic, lined up with the LED centers. These only need to be 1cm square, that will block the bulk of the intensity.

4) combine 1 & 3, attaching the tape to the diffuser. This might be preferred as you can more easily remove the tape a few at a time to increase intensity, and the tape won't leave goo behind on the scrubber (since it is on the diffuser)

Keep in mind, a lot of factors that affect how a scrubber works are dependent on your tank. For this reason, I try to stay away from some "hard line" do's and don'ts - what works for some may not work for you.

HTH
Bud

 

[HarrisonMG]

It's really the other way around - you should size the screen according to your bioload, which is primarily related to how much you feed.

It appears that you might have used the previous guideline, which was based on tank volume? But I think you are running one-sided, so that's a factor.

8.5x11, less the 1.5", 7x11 = 77 sq in, at 12 sq in/cube/day that's over 6 cubes/day capacity, then cut that in half (or more) for single sided, you're at 3 cubes/day. So maybe not that far off, but the point being that if you feed 2-3 cubes/day, you could have built a screen with an active growth area of 36 sq in and light it on both sides - would take up less room and you wouldn't need as much flow (smaller pump, less heat, less power, etc)

I'm in agreement that the light is maybe a bit much, at least initially. You may get bald spots in front of the LEDs, or if they are overall just too intense, the entire center of the screen will be bare and it will get growth around the edges - but should eventually fill in (might take a while).

As for flow, your max flow should be 35 GPH/in of screen width. You can start out with a lot less, as the initial break-in period doesn't really require a ton of flow. You could drop it down to 25 GPH/in or maybe less - the thing to do is just adjust the flow so that you get coverage on most of the screen without arcing (too much) or leaving the far end dry (too little).

Back to the light - intensity is good, if you have the nutrients to support it and the algae growth is mature. Initially, high intensity is growth-prohibitive. In order to knock down the intensity, you first have to consider the fixture and what it prevents you from doing.

In this case, I'm willing to bet that the front panel of the fixture is glass, and it gets hot after it's been running for a few hours. So I would not use any type of cloth that gets into direct contact with the fixture, and I would not attach anything to the front of the fixture or the glass. No tape, no diffuser, etc.

What I would instead do is one of the following:

1) get a piece of diffuser from Home Depot/Lowes/etc and cut it to match the footprint of the light, then attach that to the clear scrubber panel. This stuff is like what is in a 2'x4' recessed ceiling grid light fixture. It is smooth on one side, and bumpy on the other. Cut carefully as it shatters, it's best to use a razor knife and make multiple passes before snapping it (and wear eye protection, and use gloves...trust me on this!)

2) if you use a cloth, attach to the scrubber clear acrylic.

3) add pieces of blue painters tape on the scrubber clear acrylic, lined up with the LED centers. These only need to be 1cm square, that will block the bulk of the intensity.

4) combine 1 & 3, attaching the tape to the diffuser. This might be preferred as you can more easily remove the tape a few at a time to increase intensity, and the tape won't leave goo behind on the scrubber (since it is on the diffuser)

Keep in mind, a lot of factors that affect how a scrubber works are dependent on your tank. For this reason, I try to stay away from some "hard line" do's and don'ts - what works for some may not work for you.

HTH
Bud

Wow, thanks! Surprisingly, the front panel of the light doesn't get much more than warm; I think the cooling seems very good on the unit, but what do I know?
I guess I just didn't want the double sided, between needing to buy more lights, come up with a different (and more destructive to my stand) way to mount, and have less space between scrubber and sump. Really, all I care is that it works -- it doesn't have to be the most efficient in the world
But if I find that I am struggling to grow and my nutrients are still noticeable, maybe I would have to reconsider things.

As for feeding, I've been doing more lately so it's sized well for increased capacity down the road. I feed a lot of seaweed, which accounts for most of my bio load. But yes currently its oversized.

Rn I just have a sheet of paper on the scrubber wall...nothing fancy at all. It dims it down to a really nice level, compared to "holy crap I'm going blind" so maybe it will be a starting point? Idk if I get to it I might do painter's tape or cloth or something, as you suggested.

Thanks again!

 

[Floyd R Turbo]

Any sheet that is pretty much opaque is going to significantly cut down the intensity - maybe too much. So that is a very short-term solution, once you start getting some kind of growth (which might take a few weeks) you will want to increase the intensity. So you might use the paper for a week or two, then switch to something more translucent or go to the diffuser.

Remember, a scrubber isn't truly "plug & play". Meaning, it doesn't typically start knocking nutrients down from day one - you have to have algae growing to do that, and that takes time.

So for right now, you kind of have to just leave the scrubber be and let the growth progress guide you to the next step. Algae will grow according to the conditions, so to a great extent, you can't force it. You just have to let it happen.

Modifying/adjusting the lighting intensity is the best thing you can do right now. Photoperiod is the other - depending on the intensity that you end up getting, 9-12 hrs/day is likely the best starting point, and then when you start to get some level of growth, you can extend that (leaving the paper in place) and go up to 16, 18, 20 hrs/day.

Intensity determined the instantaneous rate of growth, so if you get that in balance, then you can run long hours.

Once you can increase the intensity (removing the paper and switching to a diffuser) then you will want to "reset" back to 9-12 hrs/day and re-evaluate after a few cycles of growth.

Also do not over-clean during the initial growth period. You should only need to rub the screen with your fingertips while rinsing under running tap water, and you can do this every 7-10 days or more often if you get slime growth (likely). You will want to clear the slime off as this tends to inhibit GHA

 

[HarrisonMG]

This is fantastic advice thank you so much.
Maybe after paper I could continue with my cheap endeavors and use a sheet of vellum, but if I find myself at depot, get the diffuser.

Looking forward to some scrubbing, I am really excited about this method of filtration as I have only used GFO and biopellets (and disliked the effects of both) and my friends swear by using fuges (same principal)

I also want my Orchid Leopard Wrasse to get some new munchies!

Best,
Harrison

 

[SantaMonica]

Fun growth pic.

Here is what most people want: Packed, fluffy green growth. However, this green growth is not always needed. Dark/black slime is great at absorbing nutrients out of the water when the nutrients are very high. And, light brown growth is good when nutrients are not too high. But it's ok to have your salad and eat it too.

 

[Floyd R Turbo]

Do you actually promote people eating algae from their reef tank???

 

[SantaMonica]

Here is a common growth pattern. Some green hair is on the strings, and some dark/black slime is on the rocks. Although there are some differences between the materials of the rocks and the strings, the main reason for the difference in growth is probably the proximity to the lights: More light is in the middle, and more light usually grows lighter/green color growth unless the nutrients in the water are too low: