Cheap dosing pump!!
Check this out, its a vacuum operated pump that can be used for dosing.Tom Aqua Lifter
I just ordered one to see how it works. I'll let you know. At $10 this might be the ticket.
FILSTAR Pimp #2
75 gal heavily planted,50/50 Black beauty,Eco-complete substrate, Pressurised CO2 with solenoid, ph controller, AB Reactor 1000, 330 watts 9325K GE PC lighting,Ehiem Liquidoser, 2-Filstar xp3 canisters.