Wow, your own liner change! That must have been a project. What resource did you use (if any) to learn how to do that? Any particular page you could point me to to learn more about foam cove and wall foam?
There are dozens of people on this forum who have done their own ABG liner change, and plenty of articles and walkthrough as well. Search for liner replacement.
Replacing an in-ground liner is a bit trickier, but an ABG is really not that hard, especially if you plan correctly, do it when the weather is compatible, and have enough help. I did the vast majority of it by myself, and my wife helped for a bit with the actually hanging of the new liner.
All ABG pools need a cove. The cove is an angled slope between the wall and the floor. If you do not have a cove, the liner can be forced out between the wall and floor seam because of water pressure. The cove can be made from sand or you can get foam cove. Both are totally acceptable. With sand you need to be a little careful not to disrupt it as you put the liner in. It can also be little fussy to get it exactly the same all the way around the pool. Foam cove is a triangle shaped piece of foam about 3 feet long. Most have a peel and stick backing. You stick as many as you need around the floor/wall joint of your pool. It is a consistent shape, and does not get deformed.
Wall foam is pretty much what it sounds like. A sheet of foam, about 1/4" thick that your put on the inside of your pool wall before installing your liner. It is supposed to help insulate the pool and make the walls feel nice. You attach it with spray adhesive to the wall. I found it a pain to get installed, it kept coming unstuck, and it was a bear to get the wrinkles out. With the water in, it gets compressed to about an 1/8", making me doubt there is much insulating effectiveness. It does make the walls feel slightly soft, but since I don't really rub up against the walls of my pool, I really don't get much out of that. There is nothing wrong with it, I just don't think there is that much of a benefit.
There are a bunch of bottom treatments as well. Some people use sand, some use vermiculite, some use a commercial pad such as a gorilla pad, some use foam insulation panels, and some use a combo of two or more of them. All have their pluses and minuses. I do think I will use a gorilla pad next time. I spent a LOT of time going over my pool bottom sand after I removed my old liner, and I still somehow have two small rocks under my liner, I have feel them poking into the bottom. It's been 4-5 years now with no puncture, but still I wish they were not there. Plus, if people stop on the bottom of my pool, it puts dents in there sand, and it becomes harder to vacuum.
