# Algae in fish only tank



## studioac (Nov 25, 2011)

I have a 90 gallon fo tank, with rocks, shells, and some ceramic decorations, crushed coral substrate. Tank has been running for about 3 months. Water parameters excellent, fish are doing great. Have some diatoms but they seem to be decreasing, now more green on the substrate and green and purple algae growing on the rocks and decorations. My question is should I brush off this algae or leave it on the rocks. I know for FOWLR setup some algae is desirable but what about for fish only?


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## Reefing Madness (Jun 26, 2011)

All depends on what type of algae you have there. It's a Fowlr so it's up to you what you want to do with it. With your phosphates being high you will always have that. You could run a phosphate remoevr in a filter to help this out, but again its up to you. Also, you could cut back on your lighting to diminish the algae that way. The purple algae growth sounds like that Coralline Algae which is a good thing, Id leave that alone.


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## studioac (Nov 25, 2011)

Yes, I know that coralline algae is good for FOWLR tanks, but I don't have live rocks, just ordinary rocks. My question is is it OK to leave the algae on these rocks or is there some reason it should be removed?


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## Reefing Madness (Jun 26, 2011)

No reason to remove it. Up to you, some think its a problem algae just like the green is, it does tend to mess up all plastics in the tank, like intakes, and powerheads and such. But, most leave it alone.


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## studioac (Nov 25, 2011)

Thanks! That's what I needed to know. Why is green algae a problem?
_Posted via Mobile Device_


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## Reefing Madness (Jun 26, 2011)

If its Hair Algae, it will take over the tank, and it is not pleasant once its all over everything.


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## studioac (Nov 25, 2011)

I could see how that could be a problem! Fortunately I'm not dealing with that kind of algae.


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## JimBinSC (Jun 11, 2011)

Good question. I have the same one but don't want to hijack this thread with my pics. Pretty sure I'm getting hair algae. Pics are posted in my 75 Fowlr set up and filtration thread that I just keep adding to.


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## Reefing Madness (Jun 26, 2011)

JimBinSC said:


> Good question. I have the same one but don't want to hijack this thread with my pics. Pretty sure I'm getting hair algae. Pics are posted in my 75 Fowlr set up and filtration thread that I just keep adding to.


 Doesn't look like it. Looks like a normal diatom Bloom going on. You'll be fine.


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