bloom

Every time add seachem flourish I get massive algae bloom in my fish tank? I only had one plant in my fish tank?mi have got brown and black alage growing but I clean it out on the weekend I only use the liquid solution and have gravel in my tank.

I have a 70 gallon freshwater tank. It was great the first 5 months with just fish, no plants in it. Somehow I got an algae bloom in my tank and now my tank has been green ever since. The fish have all been fine, but its just hard to see them. Here's what I have done to it and my tank...