I use Sodium Nitrite (not Nitrate) and Physum 20. The Nitrite takes care of the rust and the Physum takes care of algae. It doesn't take much , works great, and is cheap.

I also use a 60 mesh screen on the return to the tank and it keeps most of the larger particles out of the tank. When I close down in the winter, I empty the tank and clean it out however I get very little sediment out of it.

I don't have the exact formula to mix the quench since the shop is closed for the winter but it's here on the zone someplace. Use the search for Sodium Nitrite and Physum.

Willy