Growing food in my fish pond

Two years ago I grew some Busy Lizzie plants in my garden pond... I simply popped them into mesh plastic bags that fruit is sold in and threaded them onto a stick which I lay across the pond 'bridge fashion'. The plants were fabulous and I have popped two into a floating basket in my pond again this year.  I've just been chatting with my neighbour about growing tomatoes and she happened to mention seeing some grown using a hydroponic method...   I now plan to see if I can grow some using the same method that I used for the previous busy Lizzie experiment. The fruit bags won't be big enough to hold the plants as they grow so I have asked Tony to start collecting milk cartons.  I want twelve and intend to thread them onto a long cane through the handles. I'll lay the whole growing system across my pond and will construct a frame at the back of the pond to support the plants as they grow tall. I want to see how they compare with tomatoes grown both in the garden and in large pots. If you try this please don't forget to poke loads of holes into the cartons as the roots need to grow into the pond water.

My pond growing system in 2018