I wouldn't have thought this could happen. I cleaned the filter, put it back together, blah blah blah, all seemed fine and went to bed. Those experienced with canisters may be thinking "I know what's coming". I woke up the next morning to hear trickling, the spray bar was ABOVE water. It wasn't before I went to bed. AAAAAAAHHHHHHH! Quick investigation revealed, duh, a leak in the filter. SOMEHOW, and I still can't figure this out, the top thingy (that the hoses connect to and it sits into the filter as a unit) didn't seal. The lever that locks them in place and allows the water to flow, won't go all the way down if the thingy isn't fully seated. But SOMEHOW it did. So water leaked into the head of the filter and out where the power cord goes in. Luckily, I took a tip from this forum to place a kitty litter pan under my filter. It had 3 to 4 inches of water in it. So I took the head off, put it back on, and started it back up with no problem. Phew!
And I would still recommend these filters!!!!
Just thought I'd share.

And I would still recommend these filters!!!!
Just thought I'd share.