Might do OK in an unheated greenhouse. If you can, why not try some in the greenhouse and a little bit in a bowl on your brightest windowsill indoors? You only need one plant to survive the winter, and it'll grow like wildfire when you put it back in your pond.
I have heard of people suggesting keeping it in a shallow bowl of wet sand over the winter, but I don't know why that should be better, and I've never done it myself.
i've got over 100 plants,got 75 tanks but most are low light and a few with a bit of salt.tried a few lettuce in the tanks and they didn't do that well.think i'll put a few in the conservatory and a few in the greenhouse
It will definitely survive in a tropical tank between 10-28 oC
I put 4 in my tank 2 weeks ago, now must have 100 plants!!
Thinking of getting rid though as roots are about 150mm long & look unsightly!!
Condensation dripping onto the leaves can be an issue with floating plants. Drips onto the leaves cause localised rotting which can spread. Make sure if they're under hoods that this doesn't happen will help a lot with keeping them.
I kept six from last year, put them in a 100L with 2 x39w T5s, and I've had so many, I've had toto compost them monthly.
I tried twelve really big ones out in the pond two weeks ago, but it was obviously too cold, or I should have hardened them off first. Anyway, I've kept the twelve biggest and healthiest, and I'll try again at the end of the month.
The hardest thing with WL indoors is taking them out to clean the tank and putting them back in. The growing etc just happens !