Well, not quite ready to give up

Just got home to a locked up reactor. So i start fiddling with things to see what I can do. Now when I say locked, it means that there is about 2" of gas in the top of the reactor, a definite water level with no churning. Normal or initial operation is dozens of bubbles in what looks like a blender(see first pic), mixing in the reactor. This in turn sends hundreds of tiny(micro) bubbles out of the reactor and in to the tank. At some point during the day the gas builds up(with the venturi loop in either position fully open)and stops 95% of the flow out of the reactor.

First thing I tried was to pinch off the factory loop from the powerhead output to the powerhead intake. Thinking that this was simply circulating air once the lock occurred. I noticed a very slight difference in operation, the venturi started sucking more water/less air. Flow was still down 90%. Then watching a lot of air moving through the venturi loop, I closed the valve on the venturi loop. Lock instantly broke and reactor returned to normal operation(see first pic) This is what is normal in the first part of the day. Also many micro bubbles entering the tank via the reactor(see second pic)
Will watch and see if this will last daily/weekly without a lockup.

Chris

Chris,

FWIW...

I think Tom was right when he said you might need a Rio 800 or 1000. They make a Rio RVT 800 with venturi loops already built in (maybe your 600 has them too), which is what I used for my external reactor. I think they are available for under $20. There are non-RVT 800s, but it would be easier to use an RVT.

Honestly, even the 800 was a little underpowered in my case, because occasionally my reactor wouldn't fill completely upon startup if the reactor had been partially drained by a water change. Then mine would go into the same state as yours, but that was at startup. I ended up having to put a bleeder valve in the top to be used at startup (after a water change only) just to get the reactor filled and going quickly.

I see an overflow on this tank as well, this might be the source of the off gassing and why you need more flow etc.

Regards,
Tom Barr

Thanks Tom and Ted for the reply.

I will get a Roi 800 with venturi and have it on standby. Will get back on how the 600 performs.

Chris

Yes, that is a CPR overflow into custom sump(your design) Works very well. Overflow sealed with clear duct tape and sump sealed with window/door weather stripping.

I've just build Tom's external reactor. I haven't use a powerhead. I hooked up my unit to eheim canister filter and I don't see mist coming out of the outlet line in my tank. When the CO is on I can see a dramatic drop of PH in the water. It looks that everything is working perfectly - no leaks, nothing. Here comes the question: Do I have to see mist coming out of it or this unit is so efficient that almost 100% of Co2 is being dissolved in the water?

Do you use a drop checker? Or do you see plants pearling?

Grafalski,

I didn't see misting from mine until the afternoon sometime. When there is no misting, the CO2 is completely dissolving as you surmised -- that's a good thing! If you never see misting in the afternoons, you may not be getting enough CO2. A drop checker is the only sure way to know if you are getting close to the 30ppm that is normally recommended.

It's a new setup - no plants, no fish. I have a a drop checker that shows yellow color when the CO2 bubble rate is high.

Hi, I just did this DIY reactor and I think it is working properly. I am getting pearling and my pH is dropping. My only concern is that at the end of the day (~4hrs before CO2 cuts out) I get a lot of bubbles coming from the top venturi. Is it because a large bubble is accumulating at the top?

I use a 400l/h powerhead in a 55g tank.