Welcome to the forum!

Typically a lined pond has the liner covered with dirt anywhere from 6"-18" thick, usually it's on the thicker side.

You'll have to reduce the slope to keep material on the liner, stay around 3:1, go up to 6:1 for a beach area.

Call the guys at BTL Liners @ (541) 447-0712. They are great to work with and they will give you all the info you want even if you don't order from them. Their liners are pretty durn tough and are a lot lighter weight than the EDPM liners.

As for covering the liner, use dirt without rocks in it, for the beach area use pea gravel. You can cut shelves or ridges in the underlayment to help keep things in place, but ultimately it will all depend on the slope of the bottom of the pond.

Yes the water is staying clean because of what you are pumping in. You will need some underwater plants in there to help keep the water clean. It'd take a HUGE filter. 1/4 acre 12" deep is 81,400 gallons. You have roughly about 100,000 gallons of water less than an Olympic swimming pool has, so a filter has to be sized accordingly if you go that route.


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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).