I can usually get the used 275 gallon totes around here for $20-$50. The price seems to depend on the nastiness of the residual product that needs to be scrubbed out.

They should be easier to clean if you are cutting off the top.

I see people using them for a million different options. I have quite a few set up at the farm as drip irrigation reservoirs for new trees. The cages ARE NOT rusting in that scenario. I hope the cages would last a few years immersed in the pond.

Ideas: I think you could use them for plants at several different pond "elevations". You can cut off the plastic shell at your preferred height and still use the cage.

For "wet foot" shore plants you could set the tote at the shoreline and open the bottom valve for wet soil at the roots and dry soil above.

For shallow water plants, you could put good topsoil in the tub and set it at your preferred water depth. You could probably even fence the cage to keep turtles out - small fish in as needed.

Finally, you could probably support the shell off of the bottom of the cage with some "floor joists". You could put in appropriate soil for water plants and make the soil depth at the optimum water depth. The lower part of the tote cage in the water would be both fish structure and fish shade.

Obviously - I really like your idea. I may have to pick up another set of totes the next time somebody is selling them at a good price!