Algae Scrubber Basics

[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:

 

[HarrisonMG]

Mine's started filling in!

<iframe src="https://drive.google.com/file/d/1NihICnvmL71K5PaXuvnpOT_k4Y5wM16M/preview" width="640" height="480"></iframe>

 

[SantaMonica]

Try to up the lights, and on both sides of course.

 

[HarrisonMG]

So, I increased the lights and now lots more growth, some thick parts in places.
But in the three or so inches below the waterline, as you can see in the pictures, is a thick sludge of algae growing there too. Should I get rid of all of this, or let it keep growing until I clean out the screen? Is it not as beneficial as the algae that will grow on the screen? Of course, it's harder to clean too since the entire unit has to be taken off the wall (not a big deal though)

Is there a way to prevent algae from growing there? The light is above it, not in front, so it would have to be something on the inside of the scrubber.

Thanks!

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<iframe src="https://drive.google.com/file/d/1NkhiABxZE-GESuiLxU6nOpdxl2_4g5Ap/preview" width="640" height="480"></iframe>

 

[Floyd R Turbo]

That's actually the most beneficial growth - the "3D growth". That's why I designed my scrubber the way I did, to promote that type of growth. In your particular setup, I can see it being problematic because of the position of the drains.

 

[HarrisonMG]

Oh, cool! Did not think that would be ideal, especially since cleaning it means removing the unit. But....ok, it's growing back anyways!

The secondary and emergency drains are at or above water level, so they are not relevant, but the primary drain could be impacted because it opens right at the acrylic wall. I guess if I remove the "3D growth" before it starts getting sucked down the drain, then it shouldn't be an issue. Otherwise I could probably use some spare parts and get it away from growth.

I cleaned the scrubber about a week ago, and only took out the brownish red hair algae. It has almost completely grown back, and the green stuff has grown too. But since my system has seemed to have selected both as what will grow, should I treat them equally with my scraping?

Thanks!

 

[Floyd R Turbo]

If it's hair algae, leave it. If it's slime or goo, it will come off easily.

My method is this: swipe your palm across the screen while rinsing. This will remove slime and gooey/spongey stuff. Then use your fingertips and rub gently under running water; this will remove some of the more loosely attached algae (hopefully no more than 25%)

Here are my thoughts on screen start-up vs long term, and why you shouldn't worry about or try to force a specific type of growth.

Different algaes will tend to pop up depending on the nutrient/chemical balance. Sometimes, when you start up a scrubber, things are set up for growing multiple types of algae well. Then, over time, levels change and one algae ends up with better conditions, and that algae become dominant. Between that point and the starting point, the scrubber can be all over the map. I've had orange goo, yellow spongey growth, dense/dark GHA with a reddish slime coating that looks black under red light, etc. It was that way for months, and then it was like someone flipped a switch and I got explosive GHA growth and pretty much nothing else. This was on my personal tank where I was testing versions and the nutrients had risen, so it was sort of like a semi-mature tank that had not had a scrubber on it (effectively). I have seen similar patterns on other similar tanks. But that's it - just a pattern.

 

[SantaMonica]

Speaking of growth on the glass, here is an upflow scrubber looking through the sump glass, with the growth light removed. The strings are shown touching (and rubbing) the glass, and when bubbles are rapid this has the effect of cleaning growth off of the glass so that more light gets through.

 

[LQT]

Growth from my Turbo’s Aquatics L2 Rev4 ATS running on a 57 gallon tank with only 4 fish at the moment. 16 hour photo period with the potentiometer knob still in the 6 o’clock position which is 25% intensity.

 

[Floyd R Turbo]

[MENTION=23558]LQT[/MENTION] that looks like you've got it pretty well balanced - and ready for additional bioload! How does the tank look?

 

[LQT]

Tank is looking better. Went through about a month and a half of serious GHA growth in the DT... chalking it up to new tank uglies. Did a few weeks of manual removal. The manual removal as well as the addition of more snails and a Lawnmower blenny looked like it coincided with the screen. maturing. “3D” growth finally started happening in the scrubber. Algae in the DT has since receded significantly. Hopefully the new tank uglies are finally over and the mature ATS will keep future GHA outbreaks in the DT at bay.

 

[Floyd R Turbo]

you can probably bump the photoperiod up to as long as you want, the rate of uptake is driven by the intensity so if you leave that alone, it should not over-filter. Adjusting the intensity from 25% (halfway) to 50% (knob at 3/4 of max) is where you can fiddle with it a bit. If your bioload is relatively low, you may not need much more intensity, if any. Offhand I would say it would be pretty easy to over-filter a 57g with an L2 on it, so whatever you do, watch the algae for color changes. If it gets a lot lighter and starts to turn yellow, you're pushing the edge. But if you had algae on the rocks, you could still have nutrients to pull out for a while.

New tank uglies - yes, that is a thing! #15 below

http://www.reefkeeping.com/issues/2004-01/eb/

 

[SantaMonica]

Going to be getting creative this Halloween...

 

[salty joe]

I know its probably somewhere in this 10,000 plus pages...wow what a thread! I'm hoping you guys can let me know if I'm on the right path.

I want to run eight 1W 660nm LEDs. They have a forward V of 2-2.2 and forward current of 280-350mA.

I'll need a power supply of at least 17.6V, 2.8A, which really means 24V, 4A.

I'll use four Meanwell LDD-700 drivers with each driver handling two LEDs in series.

Do I have it right?