Brown Colour Algae Like On Live Rock

[scarab]

Hi! I'm cycling my tank for about a week and discover some brown algae-like thing growing on my live rock. It doesn't grow on every rock just some. Some even have no sign of it. Some hair like thing seem to be growing from it. Anyway my tank is 42 by 24 by 24 in which work out to about 100 gallon (I think). I started with DI water. Salinity last checked was 1.023. Using 2nos 150W metal halide c/w blue actinic switch on for about 8 to 10 hours daily. Live rock was precured at farm for 2 weeks before introduction. Total live rock weight about 55 kg. Water test show low ammonia(<0.5mg/L) and nitrite (0.2mg/L). Haven't tested for nitrate yet. What are these and will it bloom in the tank? Thanks.

sorry one more thing. have been seeing air bubbles escaping from my sand bed during this period. is it normal?

[Dazza]

Its algae . Everything seems fine mate. Just no need to switch on your lights during this period to avoid alage problem lah.

[scarab]

Oh! so I should just not on lights at all???

[Kalib]

Yup. Not necessary to on lights during cycling.

[Dispar_Anthias]

hey diatom are part and puzzle of cycling... dun worry

[scarab]

ok. everyone

[hotsoup]

some clean up crews like snails should do the job of cleaning up