if you put Moina outside with such temperatures, they will reproduce much slower, so that could be very good if you leave home and need someone to take care about the culture. But if you need bigger amount of food, temperatures from 22-25 would be best. During the summer you can easily have the cultures outside and set something bigger if you need more.
White mosquito larvae, except the very biggest for smaller animals, are just fine for Paros. I feed them with grown larvae of this type on regular basis as I again have some on the garden (not all the year sadly) but I know about locality where I am able to get at least some during the whole year because they survive the winter in the larval stage. Most of the year there is plenty of them of different sizes. I would recommend everyone to find such place B).