I'm in the process of replacing my 14 year old above ground pond. My old pond was in the same spot and was framed out of used rail road ties and sprung a leak the first of July and I was having to add a couple inches of water every couple days or so. I kept adding water when needed and waiting on the weather to cool off before I started the rebuild, I couldn't work out in 98 degree heat. I decided to make the pond a little larger then the first and ordered a 60 mil 20 x 15 pond liner and with the rebuild I started the first run with 6" x 6"s x10 with rebar hammered into the ground every couple feet and into the ground at least 18" deep and from there up I am using 4"x 6"x10s connecting them with plenty of 8 and 6 inch steel timber screws. All of the new lumber is purchased as 10 foot in length which we all know that's not the true size of lumber so I measured and cut in half the end pieces to fit. I'll reconnect the electrical service to the upper end which you can see sticking up in the picture. I have one more row of the 4 x 6x10's to install and then I'll line the inside with styrofoam before I install the pad and liner and the end caps which will be 10" wide by 10 foot long. This is a picture of where I got too this weekend on the project The pond will be around 29 inches deep when I finish it. I'll dig down several inches before I install the liner to get that depth. I got my 12 fish in a temporary set up and they are doing well and are not stressed, hope to finish the project next weekend.