I have an inground 17,000 gallon pool, with a canister type filter that contains 4 cartridges (cartridge number 460, I think). The other day, I drained the filter, and all the water was chaulky white. I unsealed the filter and removed the cartridges. They were full of a white, chaulky substance that resembled extremely wet mortar. This is a first in my three years of owning the pool. Usually, the filters are just "dirty", with dirt, trapped bugs, grass clippings, etc. I can't imagine what the white substance was -- I even took a pressure washer to the filters and it took a good hour to clean the cartridges with the pressure washer. Any idea what could have caused this?
As for sterilizing the pool, we use the in-chlorinator pucks (about 3 a week, given Houston weather) along with Zappit; I put about a cup of Zappit in the pool every other day. Could that be the cause? Too much chlorine trapped in the cartridges? If that's not it, I don't know what is, since there is no construction around here which would blow dry cement powder or mortar into the pool.
Thanks for any ideas.
As for sterilizing the pool, we use the in-chlorinator pucks (about 3 a week, given Houston weather) along with Zappit; I put about a cup of Zappit in the pool every other day. Could that be the cause? Too much chlorine trapped in the cartridges? If that's not it, I don't know what is, since there is no construction around here which would blow dry cement powder or mortar into the pool.
Thanks for any ideas.