I agree with what everyone before me has already stated. The fish need clean water. I think you can feed more heavily when you are getting flow through in the spring than you can in the hot stagnant summer months. When you quit getting rain and it gets hot you should consider cutting back on your feed. Hot water carries less oxygen and when you are feeding the fish the bacteria require oxygen to digest the fish poop. without any aeration, during the hot summer months, you can have a fish kill due to low dissolved oxygen caused by excess nutrients. an aeration system can allow you to push the system but when you are feeding in the hot summer it's always a risk.