Thats what i do. I have two bottles connected with a T. I have it in a 2.5 gallon bucket with a heater i put gravel in the bottom of the bottles to keep them in place but i am sure their is a easier way to weigh them down. I get quite a steady flow during the day but if i pump up the temperature it tends to increase production but lower how long it lasts. I like it around 80 just because thats what my tanks at and that works for me.
Protien powder huh i will look into that, sounds interesting.