Hi nutrient, no algae?

[icliao]

I have come acorss some tanks with high nutrient, between 10-20 ppm NO3 and 0.1 ppm PO4 with very little, almost no algae growth on the sand and glass panel.

On the other hand, my own tank has <0.5 ppm NO3 (with LaMotte) test and undetectable (persumably below 0.01-0.02 PO4) but still get some diatom growth on the glass every 2-3 days.

Why is that?

 

[dreaminmel]

Have you tested for silica? I've always associated diatoms w/ silica which may not make it into other systems and therefore their lack of algae? Not sure, just offering a suggestion...

 

[icliao]

Thanks for your suggestion. How do you reduce Silica? I am already using RO and have 2 liter of RowaPhos in a dedicated reactor.

 

[Mr.Furious]

Try using carbon too

 

[dreaminmel]

Not sure on the silica removal quite yet... I have used tap water through a deionization unit for some time now and the silica in my tank has built up to more than 1ppm. I recently purchased an RO/DI and will be testing for silica in the output water to make sure it removes it as it's supposed to.

A lot of the media for silica removal contains copper but in the filtration forum I did have people suggest a couple kinds of media. I wasn't able to find either one available in the US...

I'd test for it first to see if you even need the media though as it may not be the problem, it was just the first suggestion that came to me when reading your post.