A usefull tip would be to place occasional blocks in the center of your farm, if you are making it in a large scale, to replenish the ice faster from the center as well as the sides it generates from.
Otherwise, your water will never freeze once youve removed all the ice. It is important to make sure that the edges of your farm have a non waterlogged blocks or are able to generate ice. Ice Is only able to form if the water being frozen is adjacent to a block.
Make sure not to allow trees or other obstacles to overhang the farm, and keep light sources at a distance, otherwise, some or all of the farm's area will not freeze.
