Help, my sand beds dirty(redhair)

[122buster]

Hey guys so I’m really getting tired of fighting this dirty sand bed issue, I’m not running a protein skimmer due to the fact that it’s a 20 gal long tank , just carbon some phosphate pads and sponge. Also curious if my KH is too high(11) my phosphate is 0 and my nitrate is 0-5, calcium 400

 

[saltyfilmfolks]

IMO , if your running an hob , make sure it gets dirty. If it's not it's not pulling out anything. I ran them for years. Actually it's more efficient at particulate removal than a skimmer.

Looks like cyano. New tank?
Water changes , stir the sand, add bottled bacteria.
If your not having any issues with the corals and running very high light then the alk is probaly fine.
If you want to experiment , pick a salt with a lower alkalinity. There's no harm in it.