Brown algae in biocube

[Rfirman]

I have started to get this brown algae at the bottom of my tank on the sand bed in by biocube 14. Can anyone help?

It is not a new tank. My tank is over a year old.

I have removed the algae numerous times with my hands and with water changes but it keeps coming back. Its been going on for a month now.
I am using distilled water but I ordered a RODI system that should be coming tomorrow. Is it my water?
Oh and i do have some green hair algae too. Any advise on how to get ride of that as well?

 

[obscurereef]

It sounds like diatoms which could even occur with an old tank. Hard to tell without a picture though. Diatoms feed off of silicates in the water so your water source is the problem. The green hair algae feeds off of nitrates and dissolved metals in the distilled water whereas the RO/DI should have zero TDS. Using RO/DI water and doing more frequent, larger water changes to keep nitrates down (even though it will appear as 0 nitrates and 0 phosphates it is b/c the algae is using it all up).

 

[Rfirman]

thanks i should get my system today. i hope it will fix this problem