Need help, outdoor enclosure

[Rover15]

I believe I went about 27-30" at the deepest section. They bobb around in there. Mostly the shallow sections. Some more than others. Some have attempted to hibernate underwater, but I have been artificially brumating them in a dedicated fridge. No filtration. The bottom is some soil and leaves. Pump is soley for creating surface agitation and circulation. Just a biological watering hole. I will be adding a few dozen minnows to control mosquito larvae. They also become a food source if they die. Insect larvae and snails are also on the menu.

I watched the video i think is cool ypu have a dedicated fridge, you never mentioned the depth of the water its why i asked.

I plan on letting mine hibernate outdoors as in ontario they used to be native here and I know with some monitoring they will be fine over winter. But id be worried if they tried to hibernate in the water :s