I am also assuming (from reading on here) that the pump is too powerful. We bought this entire pool, pump and filter used from an elderly couple about 3 or 4 yrs ago. I think they said they had used it for 6 yrs. We got a new liner when we installed pool and then the tank on the sand filter cracked the 1st or 2nd yr. It was also spitting sand into the pool and when we took it apart it had broken laterals inside so we started looking 4 a replacement sand filter.

A lady in the neighbor hood got sick of "fighting" with her pool and took a knife to it. After she ruined the liner & drained the pool, she posted everything pertaining to the pool on craigslist. We bought the sand filter, some pucks and her nice pool steps. She threw in some other kind of extra filter than can be hooked to the pump but I dont know what it is. It says "pool purifier" and appears to take cartridges. We just set that aside and replaced our cracked sand filter with hers(they were same size). Her laterals appeared to be fine, but Im interested in checkin those 2 things you mentioned: Gasket and spider thingy?
Husband is a plumber so tell me what/where to check and maybe we can figure it out!.

since the pump is prob around 10yrs old now, I figured it would bite the dust before too long. it already has to be beaten on the housing with a rock to get it going sometimes. (it will just hum when you turn it on until the breaker trips if you dont bang on top of the motor) Other times it turns on with no prob. When it finally "dies", im for sure going with a smaller pump! I really think it would help things.

Finally: Yesterday, I had to rush out and didnt get home until 10pm so I just now tested.
FC dropped from 9 to 6.5 in 2 days( no bleach or shock added during that time but there is a floater with pucks)
CC is 0
PH still less than 7.2 (so i added another cup or 2 of borax)
It hasnt rained for a week, temps are 75 to 80, 60 at night. Now that its quit raining, water level is no longer holding steady, its dropped 3in this week. So as soon as the water gets warm enough I wanna get in there and try to find that leak...............