Brown Algae taking over tank!

[epjan7]

My 20g cycled tank is now completely covered in brown, rust colored stuff. When I vaccuum gravel it wont come off... its covering my glass and plants too.
I have mollies who nibble on it. But every day its getting worse.

I have 4 plants. Nitrates are 20ppm and pH is 8.

I use flourish excel every other day and flourish once a week if I remember.
I also add equilibrium for gh.

My lights are on 8-12 hours a day 48w.

Does the stuff I add increase the brown diatoms or is it just happening because its only been 2 months since cycle completed?

Any tips for getting rid of this quickly without killing plants?

 

[wildroseofky]

Diatoms show up when there is silicate in the sand. It will go away just give it time. It can take a couple of months. Nothing seems to help get rid of it sooner.

 

[Rivercats]

Diatoms are generally always present in newly set up tanks and since they are self limiting they will go away on their own once excess silicates are used up. By only running lights 6 hours daily there will be less diatom growth and then if you'd add a few nerite snails, which can't reproduce in freshwater, they will gladly eat the diatoms that do form.

 

[Rivercats]

Why do you use equilibrium? Does your water have a low gh and kh? Or are you keeping fish that need harder water with a higher ph?

 

[epjan7]

Yeah I have mollies and they were acting all lethargic and my pH was having huge swings. Kh was 0 and gh was 2 so I hardened up the water and they are good now lol