The minimum dose is 1ml at a time (per month if you want). I have a small tank that consumes 1.5ml of calcium and Alk per day, so I diluted the solution by 50% and dose 3 times a day for each, which equals 1.5ml each... problem solved...
Some vendors sell them with a tubing holder, get one if you can
Over a month of use here and no issues, easy to program, easy to calibrate if needed. Ordered 2 more
