I have read and seen several videos on how sand filters work better as they start to capture materials. The idea is that the filter will capture finer material as the coarser pathways start to get filled. One video suggested that pressure should not be the determining factor to backwash the filter, and that the flow should be the determining factor. He also stated that people will call him and say that their sand filter is not working and his advice is to quit backwashing so much and let the filter run for longer periods.
Well, I took that advice. I checked the flow every day and it seemed good. The input skimmer was working well and the output jet seemed like it was putting out a good amount of water.
Today (5/16), it seemed a little slow so I decided to backwash. The last time I backwashed was 5/10. The backwash flow started good and then nearly stopped. I switched to rince, ran it for a few seconds, then to backwash. Same thing. The flow was very low and the filter head pressure was very high. Also significant amount of sand also came out during the second backwash.
I opened the sand canister and found a compact layer of material about 1/2" to 3/4" thick on top of the sand. It had broken up a little from the backwashing, but for the most part it was still solid. It had the constancy of wet cardboard. I suspect that it was tree pollen. We are surrounded by 100's of oak trees and around this time of year everything gets coated with it.
So, lesson learned. Maybe this time of year is not a good time to wait so long between backwashings. Or maybe I took some bad advice. No harm no foul. Lost a little bit of sand, but I have more.
Cheers.
Well, I took that advice. I checked the flow every day and it seemed good. The input skimmer was working well and the output jet seemed like it was putting out a good amount of water.
Today (5/16), it seemed a little slow so I decided to backwash. The last time I backwashed was 5/10. The backwash flow started good and then nearly stopped. I switched to rince, ran it for a few seconds, then to backwash. Same thing. The flow was very low and the filter head pressure was very high. Also significant amount of sand also came out during the second backwash.
I opened the sand canister and found a compact layer of material about 1/2" to 3/4" thick on top of the sand. It had broken up a little from the backwashing, but for the most part it was still solid. It had the constancy of wet cardboard. I suspect that it was tree pollen. We are surrounded by 100's of oak trees and around this time of year everything gets coated with it.
So, lesson learned. Maybe this time of year is not a good time to wait so long between backwashings. Or maybe I took some bad advice. No harm no foul. Lost a little bit of sand, but I have more.
Cheers.