Can anyone help me?

[Grippe]

I have a red algae growing all over my sand in my 180 gallon saltwater tank. Its becoming a problem and i bought a diamond golby to help with cleaning the sand and it worked or a few weeks but recently i bought a new light and now its even worse. I also didnt want to buy any chemicals to kill the algae because i heard chemicals can mess your whole tank up and kill alot of corals and live rock. Dose anyone have any suggestions to what i should do?

Thanks

 

[Kevbrew]

I gt this on my tank but i moved my circulation jets and moved them lower to the base and it seems to cleared up plus my red legged crabs it stuff like tht which helps.

 

[Rutrag]

What is your source for water changes? (RO, tap?). Also, check both nitrates and phosphates on your source water and in the tank. Cyanobacteria usually is the result of nitrates. Higher flow helps as well.