Help ridding my 75 of diatoms (brown algae)

[Almonz]

So I have been having a little bit of a problem with brown algae growing in my 75 gallon community tank. Here's all the info. The tank has been cycled for about 8 months now, and I know diatoms have a tendency to show up with new tanks, but at this age shouldn't it be gone by now? It's not bad at all, there's just a light layer on some of the decor (the ones closest to my light) and towards the end of the week when a water change is due there are some spots on the glass in the center which I scrape off with the WC. The "problem" started a couple months ago if I had to guess, but I haven't really kept track. I have ruled out poor water condition as it is right around 10-20 nitrates, 20 being towards the end of the week. All of my fish seem very healthy. There is a juvenile German Blue Ram in the tank that does excellent, and since they are sensitive fish I have a feeling it has nothing to do with bad water otherwise I believe he would be the first to show discomfort.

The weird thing is I do not have this problem in my piranha tank which has been cycled for about a year, yet never had the problem to begin with - so that rules out tap water issues. The only difference I can think of is that my 75 has a light that is on during the day, whereas the piranha tank has no overhead light.

It's not overrunning my tank by any means, but it is a little unsightly. My guess is it has to do with the lighting, but I figured I'd try to get some input on this issue. Could it be poor water movement? The only filter I have on it is my AC110, I plan on adding another once I have some more money though. Maybe overfeeding, but like I said nitrates are under control so I don't think that's the issue. I'm stumped

 

[Mebbid]

What rock and substrate do you use?

 

[Almonz]

I use play sand, decor is artificial besides a couple larger pieces of driftwood.

 

[zer0signal]

I use play sand, decor is artificial besides a couple larger pieces of driftwood.

Hmm, I know sand can have Silicates in it, which is one thing Diatoms can feed off of, the other thing is Phosphate. I assume you're using tap water, just like your pirannah tank. So if that Tank does not have any issues, it could rule out phosphates in your tap water, leaving you with just silicates. But the only way to truly know would be to test what levels are in your tank and tap water.

I know there is a few chemical compounds you can put in your filter (Phosorb, and Chemi-Pure Elite), that absorb phosphate and silicate. But that could hamper live plants if you're growing them. Honestly I have never tried either of them, so I would be hesitant to suggest. The best thing would be API Phosphate Test, and Silicate Test.

 

[Almonz]

Once I get paid I'll grab a silicate test and see what I can find out. Thanks for the help

 

[zer0signal]

Another thing you could look at doing is picking up a couple of otto's, they feast on diatoms.

 

[ImACoolguy]

Once the diatoms eat all the silicates it will die off.

Silicates likely cam from the play sand.


Caleb

 

[zer0signal]

Once the diatoms eat all the silicates it will die off.

Silicates likely cam from the play sand.


Caleb

Yeah, That is what I was not sure of; if it would forever produce silicates or not. Thx Caleb!