Dosing pump and AWC

[bmwaaron]

I had a few questions regarding the GHL dosing pumps. I wanted to buy a 4 dose unit the first pump to dose MB7 and second for Carbon source. The 3rd and 4th I was thinking about using to do a 2 gallon daily water change. I would want to run both pumps at the same time. The manual says it can dose 40 liters a day which would mean the pumps would only run 20% of its daily recommendation. Is this OK?

A couple other questions

Does head pressure effect the pump? If I used the pump for water changes the drain would have to go about 20 feet, this would be horizontal and not vertical.
How long can the inlet line to the pump be?
Are these pumps noisy?

[Matthias]

The manual says it can dose 40 liters a day which would mean the pumps would only run 20% of its daily recommendation. Is this OK?

yes

If I used the pump for water changes the drain would have to go about 20 feet

This is about 6 metres? I don't think that this is a problem. Maybe someone can share his experience here with long lines from/to the dosing pump?

Are these pumps noisy?

I don't think so