The new dos qd is what I’m using. So far so good. Have you heard how quick ppl are buying out the DOS? 2-3 years? How many gallons are they changing per day?I have hard of a LOT of people burning out the old DOS when they tried to use it as a Auto Water Change.
I would probably use a Kaomer high vol. peristalic pump if you needed exact dosage, or you can probably put a water sensor for high and low in your sump, and have some form of pump or valve to discharge water as each sensors was triggered.
But i would definitely not use an expensive as heck DoS, and burning out a new QD even for this type of task would just eat at me.
They even recommend against using a DoS for Kalk Stirrers, but i think many of us are doing that, but i would call that probably the upper limit for a DoS.
I’m interested in reading threads about the DOS crapping out.