I'm watching this thread closely. Correct me if I'm wrong but with twp part you'll have to keep increasing your dosing volume as the amount of coral you have in your tank. At least that's what I'm experiencing. Is there a way to monitor with two part to adjust the dosage without having to adjust timers for dosing pumps? With a reactor and controller I would think it should adjust automatically and keep itself stable. The thing that I don't like about the reactor is that it seems like the weakest link is the pH probe. I've read horror stories of those going bad. How would you implement a backup?