Old Fridge for Tank

I would like to use a old fridge for a tank for fish in my aquaponic system.

If I can find one that holds a 100 gallans, it would be best, but probably anything that holds 50 gallans or more should work.

Should be insolated well when the lid is close therefore heating should be minimal. Pumping air in with an air stone should keep the keep oxigen in the water. How do tilapia do in the dark?

If it was in a green house I could open the lid during the warmer hours when the sun is out and close it at night.

Remove out the shelving and anything else that would take up space.

Line with plastic sheeting.

How big does the container need to be?

1 cubic foot

=

7.48 gallons

=

62.4 pounds

100 gallons = 13.37 cubic feet

Small fridge is 18.2 cubic feet or 136.14 gallons

Will need a piece of plastic sheeting 8x11 feet. Cost will be less than $3 per sheet. (I may even have some already in the garage).

Duct Tape 15 feet. Cost less than $0.50.

Looks like I might be able to get 136 gallons for less than $4.

That would be 3 cents a gallon for a container. And this is an insulated container. Have I missed anything?

This set a new standard in buying tanks.

It sure would be neat if I could tell how much power is being used.