Calcium reactor question.

[charlieborg]

How do you know your Co2 is gassing off? My Geo CR612 Calcium Reactor (or one close to it) is keeping bubbles in it all the time. My controller is cutting off the Co2 at 6.30. My question is how long does it take for the C02 to gas off?
https://www.aquariumspecialty.com/geo-cr612-calcium-reactor.html

 

[bhodges82]

What is it you mean by gassing off? The reactor will always have bubbles in it as they don't dissolve perfectly in the water. The interval between co2 solenoid cycles friends in the account of flow through the reactor so this time can vary.

 

[civics14]

6.3 seems really low. I assumed it had a lot of co2 dumped in trying to get it down that far. What is your effluent flow rate?

I run mine at a constant 6.7 @ 83 ml/min and fairly high demand.

 

[charlieborg]

Sorry for the lag in response. Been a busy week.

As for the gassing off. I thought the Co2 would disappear as it dissolved in the reactor? If not how does the reacter get rid of the bubbles from the Co2 tank? I'm doing about a bubble a second. My drip rate is about the same.

And I may be running it too low. I read somewhere to set it at between 6.2-6.4. So 6.7 is good?

Thanks for the input. I'll try to dial my ph in a little higher.

 

[civics14]

Sorry for the lag in response. Been a busy week.

As for the gassing off. I thought the Co2 would disappear as it dissolved in the reactor? If not how does the reacter get rid of the bubbles from the Co2 tank? I'm doing about a bubble a second. My drip rate is about the same.

And I may be running it too low. I read somewhere to set it at between 6.2-6.4. So 6.7 is good?

Thanks for the input. I'll try to dial my ph in a little higher.

I always have co2 at the top of my first chamber.

Also, I don’t keep it that low cause I worry about my media turning to mush. I guess you could and have a slower effluent rate since your effluent would be more concentrated.

 

[Adam]

The smaller the bubbles the quicker they dissolve. Frequent large bubbles take longer and don't fully dissolve. They make it through the impeller, up through the media and collect at the top of the reactor. Only to get sucked down to the pump again. I've seen people use a pinwheel impeller, the ones used in skimmers, to chop the bubbles better and get the co2 to dissolve faster. There's also a guy on R2R that recently posted about moving the bubble counter to right after the needle valve and inserting a RODI flow restrictor into RO tubing, the capillary style not a barrel, then connecting the tubing into the input where the bubble counter was. This was done on a Geo reactor. The result is very small bubbles going into the intake pipe to the pump, very fast co2 absorption and no bubbles at the top of the chamber.

I too think 6.2 is pretty low. Unless you've got a tank chock full of SPS like @civics14 does you don't need to be anywhere that low. He's a half point higher.
I followed the the recommendations of a well known and highly respected ARC member who's handle was Acroholic. Unfortunately he passed away several years ago. His method for tuning a CARX differs from the BRS vids below. But I still think there's good info on what BRS shows us from their testing. Dave's method was to fix the effluent flow rate at 50~60ml/min and adjust the pH level to meet the demand of the system. BRS shows us the opposite. Fix the pH at the lowest level 6.2ish and adjust the effluent rate to match the demand of the tank. I feel the BRS method not only wastes co2 but has the higher potential to turn the media to mush. I also use a peristaltic pump to control the effluent rate so it makes it easier to hold that flow rate.

Here's Dave Grimm's (acroholic's) tutorial. (This post was stickied, don't know why it's not now.)

 

[civics14]

I don't know why I typed 6.7, lol. I run it at 6.6 @ 83 ml/min.

A while ago, I use to run it at what I thought was 6.3-6.4, then realized that it was not actually that low, it was just a failing PH probe that later caused an alk swing a few months back.

Which brings me to another thing I highly recommend from my own personal failures. I no longer rely on my controller for my calc reactor, due to possibly a bad controller reading or failing PH probe (both happened to me). Instead, I measured my alk effluent output and adjusted my flow for my needs. Before, I had the controller turning off and on the co2 to hit a certain PH set point, but this is only as good as your PH reading that can be incorrect due to a bad ph probe or failing controller board.

I do like the idea of lowering my effluent rate and increasing the concentration of my effluent - mainly because I was juggling the idea that maybe this would extend the life of the head & tubing of my Kamoer dosing pump.