I have an unusual problem, at least for me. when my pump is shut off, the de from the filter leaks back into the lines. when the filter is turned back on, there is a...

We have recently opened our above-ground pool for the season and have replaced a bad multi-port valve seat and filter sand. The pump and filter are working great....

we live in spain and have a terrible problem with sulphates in the water. often the cristals will grow on the surfaces of the pool they are very shard and dangerouse....