Korallin Calcium reactor help?

[aquatechy]

I was wondering if someone could help me with my Korallin Calcium reactor...

I got it a few years ago, and it was actually working just fine. No problems with the pump or circulation - I have been feeding it with a designated feed pump, and i am allowing effluent to come out of both of the outlets. But lately, I have been having a troubling issue -

I set my bubbling rate, and come back a few hours later to find that it has gone out of control, and that gas has flooded the reactor and choked it out, while also dropping the pH of my tank (my poor fishes and corals ). I have tried tinkering with the water input and effluent, as well as some other setting, but the same thing is always happening. I am wondering what could be causing this? Is this a problem to do with the CO2 Regulator/check valve, or some of the reactor hardware? I'm at a complete loss here, any help would be greatly appreciated. I dont have a pH controller hooked up to my reactor, should i have one?