im sorry again

Question
i just cleaned his tank but it looks musty.why does it do that?

Answer
No apologies needed :)

Looks musty, like what color-whitish/grey?  Or brownish maybe?  Greenish?

How often are you changing his water out?

Did you change all the water out or only part of it?
And, did you leave the gravel in the bowl?

Christy