Low, next to NO pressure

[Poolsean]

You're going to see constant bubbles in the return line for one or two reasons. Suction side leak or cavitation.
Air leaks after the pump, will not cause bubbles (air being introduced into the lines) as this is pressure side. The ONLY exception is a venturi jet or spa hydrotherapy jet, that are designed to suck air in. Otherwise water will be pressurized out of the pipe.
Suction side leaks will appear as bubbles in the pump basket or the pump basket not being able to fill with water. Since you've managed to snake it and get it 90% filled, most likely Pat was correct in diagnosing a blockage in your suction line.
Blockage in the line will not be bubbles coming into the pump basket area, but rather, the pump basket not filling up. Can you send the snake from the skimmer side? Perhaps some straight muriatic acid into the skimmer side and let it sit an hour to let it dissolve whatever may be blocking the line?? Then flush it out with your garden hose into the skimmer port, before turning your pump back on. Watch the debris buildup in the pump basket though.

Cavitation would make your pump sound louder than normal.

[duraleigh]

Hi, everyone,

This is an interesting issue. I'm not at all confident about any blockage in the suction side however. The reason is when he switches to "waste" his pump primes but it does not prime from the "filter position". That, in my mind, eliminates the suction side since his issue only occurs in the "filter" position.

So, if that assumption is correct, the issue has to be on the pressure side. Does that make sense? If it does, what kind of restriction on the pressure side (and in the filter or filter plumbing only) could prevent the pump from priming.? I simply don't have an answer but the suction side blockage doesn't seem to work, either.

I'm particularly puzzled by the fact that, once primed, the system seems to run fairly normal (10psi, water flowing "pretty good"). If something in the system is keeping the pump from priming, wouldn't it make sense that the sytem wouldn't perform normally.

I know I've posed questions and answered nothing but it seems to me the vacuum side restriction is not correct. I sure hope there is a clear outcome on this....I'd love to know what it is.

[edarling]

I stuck my shop vac into the skimmer to blow it out to the filter. I had a DE clog in there because of adding too much without making the "DE slurry". If you have a clog in the line between the skimmer and the pump, maybe a shop vac will help you too.

Also - I figured this out b/c I turned off the skimmer input line and only used the bottom drain line. Guess what - it didn't have the flow issue. So, it was something in between the skimmer and pump. I was just glad it was a clog and not a water leak!

[lmnharris]

Well, I'm going out of town on business for a few days. This post will probably get lost, but I will re-erect as soon as I get home and am able to try the shop vac and some muratic acid. Thanks again