The only thing I don't like about this... the solution degrades somewhat over time. I let it run for two weeks before cleaning and refilling, and it isn't too bad.
Ppl have suggested HCl (hydrochloric acid) to prevent that, maybe worth a try.
For dosing of more concentrated liquids, have a look at what I just posted here:
http://www.plantedtank.net/forums/di...uid-doser.html