I have a 1000 litre IBC which fills with rainwater from shed runoff. I have a 2 inch foam insulated tin roof on it. (helps reduce algae and keeps termperature down/up.) I dont aerate it. The big breeding bristlenose tank loves the algae. The main display tank has its own uv light in the filter and a few spare bristlenose/2 big pleco's. Any temperature changes with water changes are only a couple of dregrees and if anything encorage my bristlenose to breed.
I trickle it into the tanks through a hose or add by bucket full and have had no problems.
Unless I was going to use the IBC as a fish tank I don't see the need for aeration or water movement?