My algae scrubber thread

Ok finally did some testing and got some nice pics of the results.



Results are pretty good. Its hard to tell, but I think Nitrates are down slightly from previous tests. I have done minimal water changes the last couple months.

PO4 = .03

Ca = 440

Alk = 9.184

(knock on wood) Luckily my Ca and Alk are dialed in pretty damn good and seem to just hold steady. Automated dosing has made me lazy in my testing regiment which is not a good thing LOL.



And the growth pics. This is 7 days of growth.

 

Still growing the algae. I have a full screen every week, and clean both sides at every cleaning.

phosphate .17
nitrates 10-20 - API

Everything is looking pretty good. My nitrates are very slowly going down. If I were more religious with water changes they would probably drop faster. Phosphates are a bit higher than previous tests. Might be a faulty test on my part, or it could be that they are just that high. It seemed that they have been slowly on the rise since pulling the GFO, but there may be other factors involved in that high number as well. Actual algae in the tank seems to be less, and what is there is growing much slower after I clean it off.

 

A few questions:

What is your algae scrubber photoperiod schedule?

Have you measure the flow through the scrubber? Do you have a rough idea of how much you are putting through it?

Are you removing and cleaning the false bottom with every cleaning?

Have you tested Potassium?

Do you have a spot in the middle of the screen that has less growth than the rest of the screen, or is it pretty even?

 

had to look what photoperiod I was running. Don't know where I came up with it, but I've got it on from 10pm-2am and on again from 6am to 10am.??

I measured the flow when I first set it up. did the old bucket and timer method. I can't remember what it was putting out, but it was close to what you recommended, I believe just a bit higher.

I don't clean the false bottom every cleaning, but probably every other cleaning. Right now its a PITA to get that out of there. With the new sump it will be much easier.

Don't check potassium, and probably won't. If it is out of whack I honestly won't make much of an effort to correct it LOL.

I would say the longest, and thickest growth is on the edges of the screen. But not significantly more than the center.

 

Photoperiods are probably OK, but if you have that high N and P and want to drive it down, set it to lights on at 10pm and off at 8am, 10 hour total. You could even go 12. Then increase the flow, IIRC you are running it off a plenum so you can just open a valve, right? If you set it at ~200 GPH jump it up to ~250 or even ~300 GPH. Check the inside to make sure it's draining out and not filling up the box and submerging the screen, as long as that is not happening you can push as much flow as you want through it. I have one guy who puts >400 GPH through it and his growth filled the box all the way in 5 days.

The reason I asked about potassium is that plants need NPK to grow. Algae will suck down K and it (may) get low enough to actually limit the uptake of N and P. Salifert makes a K test kit. Low K can affect corals too. This is all relatively new so if you do nothing about it, might not be a big deal. PWCs may replenish K enough.

Cleaning the false bottom every other time is fine. I asked because some don't hardly ever clean it, and then algae builds up and this can inhibit function and cause clogging.

So crank up the flow and light and see what happens. My guess is N and P will drop and growth will go up.