This is my first post, but I have been reading and learning from this site for a couple of years now. Thank you for all of the helpful information that is provided on this site. A little background: We moved into our house in the summer of 2008. We used the neighborhood "pool guy" for that summer because we knew nothing about how to take care of a pool. We had problems constantly because he only came by once a week and never really tested the water on a regular basis.
I soon stumbled onto this site and have tried to educate myself using the BBB method. I started taking care of our pool in 2009. I ordered one of the recommended kits and tested the water every day. At the end of the summer of 2009, I closed the pool following the procedures/suggestions from this site. I experienced no problems during closing and the subsequent opening in the spring of 2010. However, during closing last year, I am afraid I made a mistake. While using an air compressor to blow out the lines to the pool, I had the multiport valve in the wrong position. I am lucky to have already removed the drain plug from the filter. Air and water was accidentally forced through the filter. It escaped through the opening for the drain plug. As soon as I noticed what was happening (a few seconds later), I shut off the compressor. Water and possibly some sand escaped from the opening, although I did not observe any evidence of sand being forced through the opening (this seemed odd to me). I did not experience any other issues with last year's closing.
I opened the pool this year in mid-March. I have had one minor problem and what I think may be a major problem. The minor problem: A small leak (drip) where the PVC pipe from the pump joins the multiport valve. There was a small drip last year and it has continued this year. I noticed after opening this year that I could hear a "gurgling" noise through the jets coming into the pool. Sometimes I would see tiny air bubbles, but not usually. I believe I can replace the "plumbing" here to stop the leak.
Now the big issue: Sand has been collecting at the bottom of the pool in various places. (This has never happened before.) I tried to attach a white knee-high over each of the three eyeballs with fishing line. It was too difficult. I removed the eyeballs and was able to tie the "socks" adequately. The water did not have as much force coming into the pool because the opening was larger. For three days, there was no evidence of sand in the socks. Late this afternoon, I removed two of the socks and replaced the eyeballs (leaving one of the socks in place). After 40 minutes, there was a noticeable amount of sand on the bottom of the pool close to one of the eyeballs.
The previous owners of the house left the manual for the filter and the paperwork. It was installed in 2001. I do not believe the sand has ever been changed.
Do you think I damaged something inside my filter (a lateral, a hub, or something else)? I have a parts list and diagram of the filter. Is my only option to open the filter, remove the sand, and inspect the parts? I have only opened the filter once to peek inside last year. Do you think I would be able to change the parts if necessary? Would it be worth replacing quite a bit of the susceptible parts inside the filter if I have to change anything out? Could the spider gasket be bad?
Sorry for all of the questions. Any advice anyone could offer would be much appreciated!