Late summer 2019 bumps in the bottom of the pool started appearing. Pushed the liner up about 3 inches. The appeared in corners.


New member
Jul 10, 2018
Pool service guy who grew up In the business never saw any thing like this when closing the pool. I broke my hip in February, 2020 and wasn't able to open pool. Now I would like to resolve the problem. Pulled up a corner on the cover and liner is loose. Looked into trying something other than a liner without luck. Possible source of the problem is high level of ground water. Summer of 2019 was very rainy. Water is clear now.
My pool was installed in early 1980 before I purchased the property. Its 16 by 32, 8 feet at the deep end, about 3 1/2 feet at shallow end. Have had rodents under sidewalk which I got rid of with spearmint on cotton. Looks like they are back this winter.
Other equipment is Hayward Super Pump 700; Pentair cartridge filter, four elements, CCP320; AquaCal heat pump R410A.
Need help deciding what to do. I can try a new liner, but something has to be done with the bottom of the pool. Not sure pool service is interested in trying to resolve the problem.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Welcome to TFP.

Are the bumps in the deep end or the shallow end?

@jimmythegreek how do you deal with what sounds like critters burrowing under the pool?


TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
Morris Cnty NJ
I've never seen animals burrow under a pool. I'd guess the bumps are either water pockets or groundwater erosion remnants. Post some pics for reference
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