Mushy bottom (the pool, not me)

I have an 18' round AGP that has been installed for about 2 months. It has the sand bottom and cove. The installer told me that the sand would compact and the liner bottom would feel very hard, almost like concrete. I have found that to be true, except for one area that I noticed is obviously mushy, and easily mashes in with the weight of your feet on it. I'm wondering if this area, just maybe had a little too much sand, or possibly it's an area that we don't walk in very much and therefore hasn't been compacted yet ? or worse, it's a sign of an impending problem that I should be concerned about ?????

I'm probably just being paranoid, you know how us new pool owners are ! :)


Bob P.
pool newby
E Tn

My entire pool bottom felt equally solid from day one. We have had gopher tunnels but they would just collapse and then the felt just as solid as the rest of the pool. Hopefully this is normal for you ground conditions.

Jennifer

Hi Bob, Mushy sand is usually a sign of a hole in the liner. I would check the area very carefully.

Like Jennifer said, it should all compact the same.

Best of luck, Dennis

HRSDENNIS,

I will check the area good tomorrow after donning some goggles. However, I'm really hoping that I don't have a leak, especially since the pool is so new. And I really haven't noticed losing alot of water, I'm topping off at the rate of about 1/2 to 3/4 an inch a week, but have attributed that to temps in the mid 90's and evaporation. And I also upgraded to the 25 mm liner, it's also on the opposite end from where the kids normally play. I did notice the area after I backwashed yesterday. I didn't use the backwash hose, just sprayed it out the backwash tube and it was kinda in the same area. In your experience, could the ground have soaked up enough water to transfer to the bottom underneath the pool. I didn't notice the area near as bad today, so that kind of has me thinking it was due to the backwash (which I did longer than normal,....I also removed the drain plugs from the pump impeller housing to drain that area, as I recently had a problem with sand from vacumming clogging my impeller).

thanks,


Bob P
pool newby
E Tn.

Hi Bob, You could well be right about the filter backwash causing the problem. I hope that's all it is. A hole in the center area of the pool will allow sand into the pool area. Could that be the cause of the sand in your lint trap? Just a thought. Your evaporation sounds perfect so hopefully no leak.

Dennis

Yes, I also doubt it's a leak, even a tiny hole would allow for more loss per week that you are registering.
However, to be safe, try to empty your backwashing further away from the pool to avoid it soaking under the pool, this will tell you for sure, it would probably take close to a week for the ground under the pool to drain and become harder, but over the course of that time, you could always check your soil directly beside the wall at the soft spot to see if it's continually damp - this would be a sign of a leak.

HRSDENNIS,

No, the sand is definitely coming from the sandbags used to weigh drop the stairs. Unfortunatley, I removed the sand from its original bag and put it into the giant ziplock bags that came with the stairs. If I'd just put the original packaged sand into the bags, I probably wouldnt have the problem with sand I'm having now. Apparently, when I sunk the bags, an airbubble caused one of the bags to open and spill some, so every time your;re on the stairs, it causes a little more sand to eek out.