I think the pond is roughly 1000 gallons. It took me about 100 bags of fiber reinforced crack resistant concrete that I mixed myself with an electric mixer 2 bags at a time. The pond is two years old and hasn't leaked yet.
All the turtles are adults. The ponds other permanent residents are a few comets for mosquito control, and several brown basilisks who moved in on thier own and bask daily on the rocks.
Link

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-Jake

1.1 juvie L.t. annulata
1.1 adult/subadult L.g. californiae
1.1 adult Pseudemys nelsoni
0.1 adult Trachemys scripta elegans
0.1 mexican double yellowheaded amazon parrot