The pump should work for top offs as the aqua medic pump uses this pump. Have a look below.
And it will definately work for dosing zeo.
Aqua Medic Niveaumat Auto Top Off:
A common mistake in the aquarium hobby is to run the output from an R/O filter directly to a mechanical float switch on the aquarium filter to compensate for evaporation. An R/O filter produces its best water quality when run for an extended period of time. Therefore the ideal top-off system begins with a reservoir that is filled periodically by an extended run of the R/O filter. Water is then pumped, via a peristaltic dosing pump such as the Aqua Medic SP3000, from the R/O reservoir into the aquarium filter “on-demand” as water evaporates. Obviously this type of top-off system requires a reliable level sensing system within the aquarium filter and a switching controller to operate the top-off pump to maintain the water level. The Aqua Medic Niveaumat is an excellent integrated solution that combines the SP 3000 dosing pump with a directly connected low-voltage float switch. Everything you need in one economical package.
R/O filters produce their highest quality water when run for extended periods. Use your R/O to fill and refill a dedicated reservoir from which the Niveaumat can pull, for on demand automated top-off to compensate for evaporation.
Clean the included solenoid float switch regularly to ensure proper operation.
For marine aquaria, placing a Kalkwasser Stirrer between the Niveaumat pump outlet and the drip counter, which is delivering the top-off water, creates an excellent source of calcium and alkalinity buffering hydroxide ions.
Using the included one-way check valve (always on the suction side) ensures positive progress of the fluid through the top-off system while eliminating back-siphoning.
Replace the persitaltic tube periodically, depending on severity of duty, to maintain performance.