We need to empty pool for some warranty work so put off backwashing pool. After a while it didn't seem like a good idea to wait so we backwashed a couple of weeks ago and last week broke down the filter and cleaned that. We weren't so happy with how it was cleaning and after opening the leaf canister noticed that there were bubbles coming out of the pop ups and the returns (if I'm saying this right-the air that blows out of the sides of the pool). I've been pushing on the pop ups with the broom as in the past we didn't backwash early enough and I was told to do that to get any pebbles out of the pop ups. Now I'm noticing that a pop up or 2 have come bubbles come out when I turn it on high and now they're the only pop ups that are working. Could there be dirt or pebbles stuck in a pop up and that would cause them to not cycle or do we need to check the equipment? pb is coming out friday to start some warrantee work so I may be able to have him check it out but I always like to be prepared as it seems a lot of guys just want to change out expensive parts when not necessary, plus, good to know for next time. thx!