Originally Posted by Betowess
Congrats on the sticky. I remember reading somethin Sergio said about getting the flow at the rated amount if the peristatic is set for full output. But if you opt for a variable flow unit, the ouput was not as consistent when setting the speeds. So the long and short, don't order a variable output, just use a timer or dilution to get one's desired ferts in the tank and use a one speed (flow) unit.
That's exactly right. I had a bit of an issue with getting repeatability with the variable flow pumps the further I deviated from full throttle. SO, I run them at full throttle and adjust the time they run for instead. Pretty simple to do with the timers I'm using (X10 macros), but if you are using a timer that is adjustable in increments of minutes, etc, you'd just need to adjust the concentrations of your stock solutions accordingly. There is, in my opinion, NO need to spend the extra $$$ on the variable flow pumps.