I built an automatic fish farm in an Ice Plains biome (which I now realise was the worst idea) and the water keeps freezing, even though I placed torches above it as this thread suggests (although I believe this only melts ice, rather than prevents it from forming).
I can't place a block above the water to stop it freezing because fish farms require direct sunlight access.
How can I prevent the water from freezing?
62 Answers
I found that placing a glass block above the water prevents the water freezing while letting sunlight through
Water source blocks in a snowy biome will eventually freeze into ice if exposed to the sky from directly above, the light level immediately adjacent to the water block on all sides is less than 13, and there is at least one horizontally adjacent non-water block.
Glass above work if it doesn't conflict with the farm geometry. Another simple option is a torch, immediately adjacent to the water.
