Came here to say that sounds like a lot of dosing for a 25g tank...That is an awful lot of Esv. I dose 17 ml/day in a 90 gallon, 7 ml/day in a 40 and 2 ml/day in a 15 gallon. You need to determine alkalinity consumption and adjust your dose accordingly.
Just guessing you probably only need 3-4 ml/day.
Soak the pump in vinegar or citric acid.