Just bought a house with an in ground pool. It's around 14000 gal with a Pentair FNS 36 DE filter. When we first got the house no problems at all. About two weeks ago I ran the vacuum and after about 3/4 of the way through it started shooting the vacuumed debris back into the pool (vacuuming on filter mode). Wasn't sure what the issue was, so I just left it alone. I ran the vacuum again today (just had our second boy so we were understandably busy!) and the same thing occurred. Here's where I think I made things worse.
I thought I may need to backwash the system so I looked up the manual online and started the process. Back washed until clear, no issues. Opened the air bleeder valve according to the initial setup instructions. Turned back to the filter setting & restarted. After a bit some water started coming out of the backwash pipe so I assumed (incorrectly?) that I could close the bleeder valve. Went to the skimmer and added 1 lb of DE. Ran it for a few minutes before I realized that I needed more so bumped it up to the 3.5 lbs as recommended.
Pump started and continued to blow cloudy water back into the pool, along with other debris. When pump starts it blows a ton of air into the pool before eventually settling down. Pool is much more cloudy than it's ever been before.
Now I'm not sure how to proceed. After researching I wonder if I should have been vacuuming on waste rather than filter. But now I think I screwed it all up. Is there air in the system and is that causing problems? Is the cloudiness from DE getting shot back into the pool? Do the grids in the filter need to be cleaned or replaced?Where should I start!?!?! I'd like to at least try to resolve on my own before calling in an expert. Any help would be greatly appreciated!