Hot tub as aquaponics tank?

I could get an old Jacuzzi style hot tub for an aquaponics tank. To my mind, this seems almost perfect: a water proof container, a pump, and a heater. (I have not actually seen the tub in question; I want to know if it would be any use before I go look at it.) Would there be any problems that I have missed? I am not experienced with aquaponics, though I have read about it.

The thing you have to watch out for on hot tubs is the jet nozzle holes leaking. You can fill them, but just be aware that you will have to do it. Your better bet would be to find a small above ground swimming pool and use that. It will be a more uniform depth and will hold more water which in turn will make it easier to keep balanced

Yes they have a pump, but it is usually an oversized powerhog for the application--if it works at all.

You definitely have to worry about leaks, and the pump may or may not work--but if it is free you can spend a little to repair it and still be OK.

The problem is they are built to maximize area for minimum volume--exactly the opposite you want with a fish tank. If you have the space it isn't such a problem, though.

I am currently in the position of considering repurposing my hot tub to an aquaponics tank. One area of concern I have is that the pump may be overpowered for the purpose, not just in terms of efficiency, but in terms of excessive turbulence for whatever I might try to grow in the tank.

At the very least, it's a large thermal reserve in my greenhouse...

You could probably use the hot tub as a place for your fish to live. They don't mind water turbulance. You could even leave on the insulated cover if you cut a window into it. You would then have to plumb then hot tub and add a pump to move the water to some grow beds.

I've been thinking of adding a hot tub to an aquaponics system for use doing water changes in the winter. You bring some friends and sit int the hot tub for a while. When you're done you put on the cover and turn on the controller which drains the hot tub water into the aquaponics system when it needs heating. The excess water in the aquaponics runs through the overflow outside the greenhouse.

So, water change, system heating, and nice hot tub time with friends all in one.

I just put my old hot tub out in the yard for this reason! I but I threw a pond liner in it! Not using the pump or any tubing. Too much crap! Also don't know if there were any chemicals in it!

Glad you brought up that crucial point, thanks
Farming fish in any non -natural settings, like plastic, fiberglass, rubber,polyurethane, etc. might come at a cost.  I have used  materials like  adhesive or fiberglass, never reading precautions until days after. Maybe we all have.  But we try to improve.  Society knows we already have nanoplastics in  pregnant moms that are crossing to the young.  It is hard to ignore
petrochemicals , plastics n our air and water.   I want to try something similar to hot tub idea, but suggest a modification please:  an old school hot tub with wood and metal...think a snorkel style but probably  handmade.....that drained downhill to a fish pond dug into the soil, with or without a pond liner. Possible?  If needed, I would import clay to help a pond hold water?  I think that might be healthier for us all

Addendum
I meant to add that many Permies seem to endorse the gley method for pond making, it seems similar to a clay-soil combo for sealing an in ground pond. I admit above ground pools are fast and less work.   But I am going to try a more  laborious, slow approach.