Hello FishChick. Over feeding your fish can lead to a multitude of problems. Be careful. Make sure you do your gravel vacuums regularly. Food left in the bottom of the tank can lead to Planaria and other water issues.
Are you using
activated carbon in your filters? If so are you changing it every 3 weeks? I see that your tanks have been set up for a while so I don't think it would be an algae bloom at this point but it could be.
Although most store bought food says it won't cloud the water...if there is too much food in the tank it could be the cause.
I would do another water change, gravel vacuum...change carbon and see if it helps.
Best of luck.
Ken