Algae Scrubber Basics

[Floyd R Turbo]

I know this is OT, but sort of on...since I'm going to put a scrubber on this tank temporarily...

Started packing up everything around 1:30, took until about 3, 30 minute drive, and probably 2-3 hours to make a place for the 37g (moved 10g FW) and pick through the rocks and arrange. After a few hours, everything started coming out. Here it is right after getting the lights and a power head on:

Peppermint shrimp was hiding in the rocks

Here it is a couple hours later

3 chromis accounted for. 4th could not be found while packing or unpacking, I think he jammed himself in a rock and is toast

Leather is coming out fast!

Anthelia

Rose Bubble Anemone, GSP, Zoa

Yellow Polyps, small zoa

Ric

Fire Shrimp

 

[L33t Reefer]

Is it safe to have all that rock set up against the sides of the tank?

 

[Floyd R Turbo]

Yes? I guess I never gave it a second thought! Rock falling into glass is bad. But silicone seals hold back hundreds of pounds of pressure. What's the harm in a very slight amount of pressure from a rock leaning against glass?

 

[travis32]

I think it's the ATS it's really the only thing I changed, I hand pulled a ton of Hair algae this week. I've got a mix of macro algae- sea lettuce and chaeto also. The sea lettuce started taking over my powerheads and return outlets. I harvested some of that too this week. Between the macro algae, 6 nitrate consuming mangroves in the sump, and the ATS, I'm seeing huge improvements.

My ATS screen is solid green and dark green. I cleaned it yesterday. I was NOT able to harvest / extract a lot of stuff off the screen, it's mostly slime algae. but it's been building up. So, it's definately contributing to the reducing HA in my tank. After hand harvesting this week, I want to see if it grows back or if it's done popping up everywhere. Keep on top of it. I also found keeping Alk around 10dkh, seems to inhibit HA, and having MG around 1500 (raise very slowly if you do raise MG) also seems to limit HA growth.

I did a 30 hour lights out last week and I think I'm seeing the results of that this week, because during those 30 hours the ATS lights were on for 20 hours or so.. So, The algae had to relocate.

Eventually I'll need to pull the macros, but, for now, the combination is helping me cleanup my rocks!

 

[Floyd R Turbo]

If you had high P for a extended length of time, your rocks will absorb that like a sponge and them leech it back out once the scrubber starts knocking it down. It's that kind of situation where you will have no P but all kinds of algae growth on the rockwork. You are doing the right thing by pulling the algae out of the display, so that the scrubber can out-compete it. It will take some time for all the phosphate to leech out of the rock, just make sure your flow is enough and your lights are on 18/6 cycle.

You can test to see if your rocks are leeching by mixing up a fresh batch of water, and taking out one rock and letting it sit in the water with a power head for a week and then testing P. That's likely what it happening.

As for the alk and mag levels, you want hair algae to grow on the screen, so raising them to inhibit growth is going to stall out your screen as well (if alk/mag works). So consider that also.

The other thing to watch is feeding, if you severely restrict feeding to the point where either N or P drops out, then the absence of one limits the uptake of the other. So if you have no P, N will not get readily absorbed, and vice versa. This is called "limiting".

 

[travis32]

So maybe, lights out is the best method to get algae to relocate from the display to the Scrubber. I know I had a huge moment of growth on the scrubber when I turned the lights out for 30 hours.

I may feed more heavily to increase the capacity of the scrubber. I have a question though. I see how others posted pictures of several pounds of algae are extracted from the screen. How does one get to that? Does one stop cleaning it for a few weeks or is that something that just happens over a period of a few months if P and N continue to be introduced?

 

[srusso]

So maybe, lights out is the best method to get algae to relocate from the display to the Scrubber. I know I had a huge moment of growth on the scrubber when I turned the lights out for 30 hours.

I may feed more heavily to increase the capacity of the scrubber. I have a question though. I see how others posted pictures of several pounds of algae are extracted from the screen. How does one get to that? Does one stop cleaning it for a few weeks or is that something that just happens over a period of a few months if P and N continue to be introduced?

Thats the best part about ATS... That is what will grow in a week...

Remember nothing good happens fast in a reef tank.

 

[travis32]

Wow? A week. Must be a huge bioload or something. LOL.

 

[Floyd R Turbo]

I haven't weighed the harvest I've been getting, but it seems to be between 2 and 3 cups drained every week from a screen that is 22x7. It is very well stocked and moderately fed.

If you go more than a week, you risk detachment of algae and potential clogging if you have an enclosed/flooded box due to weight of algae, light blocking, and pods eating the algae. I talked to Santa Monica about that, he said he went 2 weeks w/o cleaning and a big chunk of algae detached and plugged the drain. So it's not recommended to go more than 7 days on a flooded box, for an open screen you could go longer, but detachment is still the main concern. Really you need to be cleaning every 7 days no matter what for a multitude of reasons.

 

[travis32]

Thanks for the clarification. Sorry, that brings up something else I noticed. I noticed I have Hair algae growing in the box just attached to the wall. I thought in general that's a good thing as it's assisting the scrubber if nothing else, It's not much and not a big issue... now. But, Is it generally a bad idea to have algae growing off the screen inside the box??

 

[Floyd R Turbo]

It's not going to stay there very well, and will probably detach and end up in your sump or DT. Not the worst thing in the world. I have algae growing on the box also, but I clean it off every week. If your box is acrylic, be sure to use a wet paper towel to do it. Worst case, use an acrylic-safe scraper to remove any tough buildup. If you scratch the acrylic enough, it will diffuse the light and your screen growth will diminish over time.

 

[richierich2000]

3000K

http://www.aghydroponics.com/T5-2Ft-Grow-Bulbs-24W-HO-3000k-p/litbulbt5-pxfl24830.htm

The slot tube size really doesn't make that much of a difference, a larger tube will allow a slightly greater flow rate, but it's the width of the slot that matters most. Santa Monica's 100 scrubber uses 3/4", I use 1", I would just match your overflow drain size.

At this rate, I'm going to go through a lot of my summary before I get a chance to post it!

I have 2 2" drain tubes so would you use one of them?

I have some 3/8 acrylic would that be to thick to use?

still not sure to go with 44"x5" or 22"x10" what would be best to clean and maintain?

 

[Floyd R Turbo]

Wow, how much flow do you have? 2 x 2" pipes is like 6000 GPH at full siphon.

The 8 pack of 24" lamps is $32, and you would need all 8. The 8 pack of 48" lamps is $50, and you would need 4. They're also higher wattage (54W vs 24W) so you would have a little better bang for the $. With a 48" pipe you will probably have to support the pipe in the middle, but that's not too big of a deal. The shorter, wider screen IMO is preferred over the taller, narrow screen, because of weight distribution and the layering effect. A tall screen will get algae up high on the screen growing long and blocking light more as you get lower on the screen. So there's a couple reasons why you would want to do 48" instead of tall 24".

 

[richierich2000]

I have a dart full blast 4' head

so is the 3/8 to thick or do I need to get 1/4"

thanks

 

[Floyd R Turbo]

I wouldn't say it's too thick, but probably not necessary. Whatever thickness you use at that width you will need to brace is with a perpendicular piece of acrylic because it will warp otherwise, so 1/4 should do fine. Worst case it will fill all the way with water, so you might want to find an aquarium calculator and enter in dimensions so it will tell you the thickness of acrylic you would want. It might not like putting in 48" wide by 9" tall by 3" deep though. I know I've seen a calculator site out there for acrylic tanks, I'll look and see.

I still think 1/4 would be fine. 3/8 gets expensive.

 

[richierich2000]

I have a dart full blast 4' head

so is the 3/8 to thick or do I need to get 1/4"

thanks

 

[salty joe]

I'd think that either would be fine structurally. It might be worthwhile to find the light transmission specs for different thickness acrylic. Who knows, it might be significant. If you go that route, would you be kind enough to post the specs?

Using an aquarium calulater to determine acrylic thickness in a scrubber would be great as long as you can plug the numbers in, as Floyd pointed out. Just for the heck of it, let's compare a scrubber that is 2"x24"x24" to a cube that is 24"x24"x24"(inside dimensions). The pressure pushing straight down will be the same PSI. However, we need to be more concerned with the pressuer pushing out on the sides. To make my point, imagine 2 pieces of 24" acrylic with a 1/64" gap between them that is filled with water. Same PSI on the bottom as the cube. This could probably be done with some pretty thin acrylic.

 

[redneckgearhead]

1/4 inch would be fine IMO, for most scrubber builds. I can't think of a reason you would need 3/8". Give us some ideas on what your plan is?

 

[richierich2000]

I already have the 3/8" I just don't want to buy a sheet of 1/4" if I don't have to

 

[richierich2000]

going to do a 48"x5"x 6" with 4x48" t-5