It was just last week I read from Oldpunk(TPT) that the milwaulkee has no check valve between the bubble counter and solenoid.
It really explained a lot to me as I lost fluid completely in days.
Super cheap buble counter @kensfish($3).Check valve is your choice but you should have one.
from OP;
Naw...
Every one of them I've read about has been a Milwaukee and the solenoid got stuck open. That means the ph controller no bad how much it wants to cut the gas, it can't.
Since the needle valve is adjusted to rapidly increase the co2 saturation, it doesn't take long to gas your livestock.
Wanna know why the solenoid got stuck? Because your water or Glycerin or whatever other fluid you have in your bubble counter has a chance to back up to the solenoid whenever it's closed. It does this because the bubble counter is mounted right onto the needle valve and there's no check valve between the two. A really poor design as far as I'm concerned. But it works anyway.
There aren't many of these type of failures and considering how many Milwaukee regs are out there, it's probably not going to happen to you. It does happen though. And every once in a while, we hear about it here on the forums.
I guess my point is that you don't want to depend on a magical piece of equipment to save you from a piece of equipment that's prone to failure. With the money spent on both, you could have just got one good piece of equipment that doesn't require maintenance and won't crap out after a couple of years. A ph controller should be used as tool to set your co2 levels. Not thought of as a way to save your livestock incase of a failure somewhere else.