Yes, you control a reactor with a PH controller. Controllers are really quite simple, and pretty much foolproof. You should embrace technology, it will hep you out Manual dosing can easily be messed up, probably quicker and worse than a reactor can mess up a tank. Actually, if you run a reactor with a ph controller, your chance of messing up a tank's chemistry is slim to none. I have come to the conclusion that those that dose 2 (3) part for a while eventually get to the point where they can't keep up demand, and end up going to a reactor. Citing the reasons they did not go with a reactor up front was due to the higher inital cost. You can automate dosing as well, for those that want to leave their house from time to time, but those pumps are $$, and pretty close to the cost of a decent reactor.