Pool Filter Tanks
Four Pentair Triton II Commercial TR140C-3 silica sand-filled filter tanks operate in parallel to capture particles in the water that passes through. As particles accumulate, flow is restricted. This is indicated by an increase in pressure. A pressure gauge and electronic sensor is present on each tank.
Channeling
Backwashing
Information regarding backwashing is available on this page.
Replacement of Sand
Filter sand should be replaced approximately every 10 years. This guidance is based upon the seasonal nature of the pool; year-round pools require replacement often at the 5 year mark (or sooner). Each tank requires about 18.5 lbs of #20 sand.
As of 2021, the last known sand replacement occurred in 2013. It appears that a course sand was used (#40 or #60, perhaps). The next replacement should coincide with marcite replacement (i.e. late 2022).