Adding to Filter..? When?

I've been reading on this forum about people adding DE or Sand to their filters.
I have Zeobrite in my filter. Do I need to add more Zeobrite occassionally?
( The pool guys left an un-opened bag of it by the filter)

If yes, then when?
Do I add on some sort of schedule? ( like every 4th backwash or something?)
Do I add more zeobrite at pool openings or closings? ( or not at all?)


Thanks for your help

RavenNS :-)
mom of three toddlers:eek: ( Whew!)

If you have the instructions for your filter, it should tell you the amount of freeboard (the distance from the sand bed to the top of the filter tank) you should have. You'll have to open the filter to determine this in your filter. If it is low, add some of the Zeobrite (probably all of the bag). Remember to backwash immediately after adding it or all of the very fine zeo material will find its way to your pool.

This will probably only happen after a few years of service. If your water is clear, don't worry about it. If not, after checking all the usual areas (water chemistry, filtration time) check the filter.

The filter is a Jacuzzi 25 sand filter, I think it's about 7 years old... I don't have the manual

The sand in it had never been replaced ( yuck)

we bought this house this last winter. Pool store people replaced the sand with Zeobrite in May ( during opening)

Thanks for the advice:)