Sounds good, you could add an aquarium filter and use an aquarium in the Viv so you can see him underwater
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Maybe get it drilled and fit a drain plug for maintenance
Along the same lines but without the viewing opportunity a tank would provide, you can get rain barrels or half barrel “ponds” that are already fitted with a drain plug that attaches to a garden hose. It should be easy enough to cutdown to the depth you want.