Brown Algae But Almost Finished Cycling

[KCB]

I've read that brown algae occurs at the start of a new tanks cycle but it has started to occur in my tank (which is fish-less cycling) over the past few days when it is almost fully cycled. Should I be concerned? It was only a tiny spot when it first started but now it is spreading rapidly over the back of the tank. Test results today are: Am: 0.12ppm, NitrIte: 0ppm.

 

[KittyKat]

That's diatoms. Rub them off (I normally use a toothbrush or non-tearing kitchen/paper towel), then do a large water change immediately afterwards. Are you keeping your lights off for the duration of the cycle? If not, this is what caused it. Keep the lights off and if in doubt, through a blanket over the tank to cut sunlight out. Once you get plants in there, they'll use up ammonia/nitrates, so you won't need to worry about it again.

See http/natureaquarium.co.uk/?p=398

 

[KCB]

Doh, yes I've been keeping the lights on for the past couple of weeks

That must be it then. I'll do what you suggested, thanks for the help