Brown Stuff Growing On Tufa Rock

[Maxta]

Put a tufa rock in 3 weeks ago to sort out my pH (which it has thankfully).

Now its starting to go a light browny colour, mostly on the top of it. Also have something growing on the front of my aquarium, again browny but isnt too bad.

Is this algae? My camera isnt good enough to get any decent close/detailed pictures.

I thought keeping the aquarium lights on for at least 8 hours a day sorted this problem? My lights are on from 8am to 1pm, then 5 til 7, on the timer, but often i leave it on til 9/10/11pm. Yesterday my timer went crazy and it was on all day

 

[Sysiphus]

Lots of good posts and discusions on brown algae so you may want to check those out. I bet that is what you have.

Brown algae is a common occurrence in a newly set up aquarium. It is generally caused by too little light, an excess of silicates, an abundance of nutrients, and too little oxygen. Silicates can build up through tap water that is high in silicic acid, and silicates that leech from some types of substrates.

Cure:

Wipe off surfaces & vacuum gravel well

Use silicate adsorbing resin in the filter (kind of extreme)

Increase the lighting

Stock a plecostomus or several otocinclus


Good Luck