Havron,
You might get by with this size, if you can beat the algae and still provide enough light. This is what I am currently doing as well, and like so many others I have problems with algae in this tank. In habitat these Utricularia are usually associated with other species that both acidifty and purify the water: a balanced ecosystem. The plants grow in full sun under these conditions, and are often sheathed in algae which acts as a sunscreen: allowing good growth but also protecting the plants. In tanks this same algae will eventually kill them, as there is nothing to check its growth. I am new to the culture of radiata, but I have grown and flowered macrorhiza in full sun in an opaque dishpan with a sheet of white plastic lying on the surface, in full sun. The size of radiata doesn't allow for a dishpan, but I wonder if a larger opaque container with similar sheeting wouldn't produce similar success. The macrorhiza is algae free: not enough light to make green soup, and the plants are protected against sunburn by the plastic. Remove the plastic and the plants would get sunburned and/or algae would be rampant. It is a difficult quandry. They need the light to flower, but must be protected at the same time. In larger tanks or ponds companion species will maintain the balance, but there isn't enough room in a 10 gallon tank to grow them and the Utricularia. I wish I could help you more. Reduced light will discourage algae, as will lower temperatures, but this is not going to promote flowering. Oh for a pond!
