Pool Startup -- Algae + DE filter

[PoolDoc]

Usually, you cannot 'snake' pool lines. A drain snake will go through DWV turns, because of the longer radius. But when you use S-40 pressure fittings, you usually can't get the snake past the first 90 degree turn . . . and there's the danger that if you DO get past the turn, you won't be able to retract the snake.

. . . people have had to dig up decks!

[bjb1966]

That makes sense. Two years ago when we were closing the pool my husband accidentally dropped a small plug down the skimmer hole (he thought it was the right one, but it wasn't). There was no way to retrieve it at the time and the pool company we use assured us that the gasket would break down over time and be fine. They also upon opening the following spring tried to blow a lot of air (i think or water) through the line to get it to come through. It never did and we have never seen it. I have a bad feeling this could be causing a problem. Possibly stuff is getting stuck around it and then free from it which is why the suction is intermittent. But we didn't have this problem last year except for that we have never had very good suction from pool skimmer or it is intermittently good.

[PoolDoc]

What kind of plug was it?

Rubber or plastic is unlikely to ever break down, but if it was something else, it might be possible to add chemicals that *would* 'eat' it up.