I'm making a pond for the first time and I knew if I planned meticulously then I'd never start so kinda just did the bare minimum thinking and got to work. I've finally dug the desired size and shape but the next step is putting me into decision paralysis so I came here hoping for some guidance.
While digging I found some dumped rubble, no doubt from when the house was built, and it means there's some jagged edges that could cause issues. I'm not sure the best way about dealing with them. I've seen people use concrete but we don't want to use that. There's a lot of conflicting info about best practices but the current thought is sand. Not sure how exactly to have the sand up the sides cleanly though for when we place the liner. I've seen a suggestion of sharp sand and get it wet to hold form but some have said that shape sand destroys pond liners over time?
I'm expecting to get a rubber liner rather than PVC in the hopes it is less susceptible to UV and weather damage. Seen people say a fabric liner between the sand and rubber is needed and others say it's useless.
I'm planning on having the water get pumped into a small shallow connected pond that the fish can't get to as a safe place for amphibians to spawn (the fish have eaten every frogspawn in the inherited pond for the last 4 years) and to work as a biofilter. Currently the biofilter section is dug to about 11cm below the lip. Would that be deep enough or is that too shallow?
Current dimensions if it changes advice given:
Purple (deepest section) 110cm each direction (average)
Red (main body of pond length) 185cm
Yellow (max width of pond) 189cm
Green (max length of entire pond footprint) 230cm
Depths: Deep 65cm, main body ledge 40cm, shallow 12cm. All those depths are from the very top lip of the lowest part of the pond (I'm on a slight hill) so actual water depth will be shallower and even more so after the sand/advised padding has been added. I'm expecting the deepest to have a true depth of 50-55cm from the water surface as that's slightly deeper than the inherited raised pond so we know the fish are fine with that depth in the winter.