In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
4 SunEarth 4' x 10' collectors
Stainless Plate Heat Exchanger (radiant); Quad Rod Heat Exchanger (DHW)
15-20 Gallon Drain-back Tank
Unpressurized Drain-back Setup
A few months after firing up my system about 2-3 years ago, I began noticing just a slight browning of the water visible through the sight glass outside my drain-back tank. It presently looks like what's shown in the attached photo.
I'm interested in hearing your thoughts on how to proceed and how much of a concern this "browning" is.