ugly tank need help

[waterdogjenn]

I have a 80gl tank that has been running for 6 mo. I can't keep the sand/crushed coral clean it has a red/burgandy color its not diatoms been there done that. I have 2 turbo snails,15 small blue leg crabs, hawk fish,perc clown and fox face. the snails keep mostly on the glass the crabs are mostly on the rock. My lights are on for about 7hrs a day they are PC. water perameters are fine I do a 10% water change every 3 wks w/RO water.
Here are some pics. Attachment 226375

 

[katsafados]

Cyanobacteria!

 

[jemshores]

IMO 10% every few weeks is not enough...for about a month, I would try 20% on a weekly basis, including you filter media. Its great you use RO water! So can't blame your "bloom" on that-but honestly-get the flow going and increase you water changes till you see some improvement. Maybe cut back on feeding and lighting too till all is better.

 

[waterdogjenn]

I have 2 power heads one in the frount of the tank blowing to the left and one in the back of the tank blowing to the right and the pump from the refuge blowing to the frount of the tank I thought that would be enough. I will definately increase the water changes.

 

[alabama reefer]

Generally cyano likes the dead areas in the tank. You will usually have some waste that collects in these areas and this helps fuel. You may need to add a little flow or redirect the flow you have now. Over feeding also helps provide nutrients for cyano. I don't think running your PC lighting 7hrs is too long but if your bulbs are old that could be contributing as well. Picking up your water changes should help and if you can syphon that cyano out when doing your changes.