Normal for DE to be in pump strainer after shutdown?

[cruzmisl]

Thanks for the responses. Upon further reflection, I think I know what is happening.

The original PB did not use any check valves in the system. I have a spa that is higher than my pool. When I shut the pump off the water tries to equalize and pushes backwards from my spa return through my pool returns and main drain/skimmer resulting in the DE in my pump. Sound possible? I bought a check valve prior to noticing this problem, just haven't installed it yet.

In the morning the pump basket is still full of water so I don't think I have a leak. Also when I installed the filter I literally weighed out the DE. I have heard of adding 80% of the suggested amount though.

Sound reasonable?

[waste]

Joe, the answer is YES - it's very reasonable Like Sean was talking about, overcharged filters will have reduced efficiency and the (without the backflow prevention) milky water in the pump. When you backwash or 'bump' the filter and open the drain valve to clean the used DE out, you only get ~ 80% out, so only put 80% back in to avoid the over charging. I'm assuming a 'bump- style' filter - if it's Hayward the 'check valve' is located in the inputpipe sometimes the weight falls off the rubber flap, other times the whole flap falls off - they can be seen and replaced by unscrewing the 'male'1/2 of the union. If you need more info on this- I'll be more than happy to help

[cruzmisl]

My filter is a Pentair FNS Plus-it doesn't have a "bump" option. I only ever cleaned it once and I took it apart and cleane dit out totally. I'm going to install the check valve tomorrow and see if that makes a difference. I'm not sure if the filter itself has a check valve. I have a multiport valve if that matters.

Thanks for the help

[waste]

From what's been posted, it's probably the water from the spa causing the backflow through the system. I'd put the check valve on the spa line, it'll stop the DE problem and keep you from having to re-fill the spa every morning.

$.02 worth