So here's a tricky one for y'all to pick apart. First, a quick background.
Tank is in a Japanese Steakhouse. 225 FOWLR. When I came across it, it looked like this
Nitrates well off the scale (over 800 on API, extrapolated after diluting sample water with fresh SW) and Phos who knows.
With 1 fish alive
And one that I found under a rock when emptying the tank, and he was blind and barely alive
He died a few weeks later.
I pulled the fish & bio-balls out into a temp tank
Soaked all the rocks in freshwater, sprayed with bleach, rinsed, etc...Then sanded down the main tank (took 2 weeks @ 2 hours/day) and set it all up again.
That was almost 3 years ago.
Now, because the owner hasn't wanted to pay for monthly water changes, and they really didn't seem to be making much of a dent, the tank is back to super high nutrients.
The result is N is over 400, and P is around 6.5, both using diluted samples. Please do not crucify me!!! LOL
I added an L2 (original version) in October of 2012. I wanted to see how it would perform. Turns out, it doesn't - at all.
The only growth I get is in the bottom of the box:
...and it's sort of like a skin of algae
Then there is some emerald green growth inside the slot pipe - deep inside it, like where there is nearly zero light, and some brown growth right at the bottom of the screen (underwater)
This is what it looks like, week after week, for over 3 months. The screen is bare white, like it was brand new, and the only growth is at the slot pipe junction and up into the pipe, and in the corners and bottom of the box.
I have tried running the lights 24/7 (for one week, a month into it) but for the most part I run the lights 1 hour on, 1 hour off, for a total "on" time of 12 hours/day.
So what is the deal here? Nutrients too high for algae to grow? No presence of proper strain of algae?
Is it just high P, just high N, or both? Could I run GFO to pull down P? I recall a thread about high P inhibiting algae growth. They clean the tank with a algae mop once a week and there is hardly any growth.
The restaurant changed owners last year, and the new owner wants to turn it into a full-blown reef tank (and so do I!!). I can do a PWC if I really need to, but it's a PITA on this tank. I was hoping that the algae scrubber would at least make a dent in the nutrients - I haven't even bothered to re-test.
To my knowledge, no one has tried putting an algae scrubber on a tank that is this high in nutrients. So maybe there is a limit to what the scrubber can do. If that is the case, this tank is well beyond it.
So I'll leave it to the study-diggers to dig up something that might explain this...