Sand turning brown

Hello my sand has been turning brown. I go and mix the sand up every couple of days cause it keeps turning brown. The tank has been running for almost a month now. The brown is growing on the walls of the tank to.Iam doing something wrong???

 

Nope this is normal.. Sounds like your cycle is in progress- what are your levels?

 

no-2 0ppm
ph 8.4
no-3 10
ammonia 0ppm

 

Just give it time you will see a couple different diatom blooms in your tank until it matures. My tank is 7 months old and I just had another diatom bloom on my sandbed, just give it time and it will go away

 

It is just diatoms and could use some cleaners. snails crabs that sort.

 

Thanks everyone for the help..