Filter laterals not completely unfolded, what happens?


Well-known member
Feb 8, 2008
Milford, CT
After opening my filter up a couple weeks ago I noted that it was low per the Hayward manual. Ended up adding about 125 lbs or so, of the 300 lbs that Hayward says the filter should take.

Lately Ive noticed some sand getting into the pool. I figured maybe it was from the new sand, etc, but while I had some time I took it ALL out to check the laterals.

They were all intact BUT NONE of them were sitting flat (each lateral on my filter folds outward once the whole center unit is in place in the filter tank). None of them looked TOO bad (not completely vertical), but I was wondering what this might cause.....Im guessing maybe some sand back in the pool? How about some smaller junk escaping the filter and getting returned back too?

BTW, Im not sure what part of the manual to trust. One chart says 300 lbs of media, the other says within 6" of the top of the tank. I had at least 300 lbs of media in there (I put some pea gravel at the bottom of the tank after reading about that trick, plus 250 lbs of new sand plus a little from what I vacuumed out because it still wasnt enough), and it wasnt close to 6" from the top of the tank. Im guessing I was closer to 350 lbs before it was close to the level.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
If the laterals were even partially folded up it would certainly allow sand to get out of the filter and into the pool.

The sand height is more important than the exact weight of sand used. Sand varies in exactly how densely it packs, so the weight needed will vary a little bit.