the liter meter 3 is a dosing pump. It is capable of several functions and can be easily recalbrated. I curently use it to top of my system at nite with CaOH(kalkwasser/lime water) via a geo Kalk Rx. It is a bit pricy around $340.00 but I do like the accuracy and the versitility of the unit it can controle up to three differrent pumps and level indicators. I would rate it as an A.
Overall the pump has done well...I did have to send it back once for repairs it started to leak. Curently I have it controled by my AC3...to control PH eventually Ill have some float switches installed. But the feature that i like the most is the automatic water change feature...thats the next thing on my endless want list.
