the sand that is in my filter now has been in there for 3 years and it it has had 3 algae cleanups through it. i was thinking that i would need to change out the sand this year so i bought some sand over the winter.
i just got the water sparkling and was about to change out the sand but i've been thinking that since the filter cleared up what looked like a pond in about three days that maybe it is just fine. i only bakckwashed one time and dont think it was anywhere near 8psi. it's a doughboy filter.