CO2 Build up

andrewb70 · Nov 9, 2020

Hi I have a Reef Octo Calcium reactor running with ARM Extra Coarse media and appear to be getting CO2 building up inside the reactor. There is a lot of bubbles being recirculated.

Tank Volume 120 Gallons mostly SPS frags - 1 year old
Ph inside reactor 6.3
Effluent dKh 13.2
Effluent Flow Rate 30ml/min - Kamoer FX-STP
30 bubbles per minute
Tank dKh steady at 8.5 - which I am happy with of course.

Seems odd that the Effluent dKh is so low at 6.3ph and the CO2 is not being absorbed ??

Any thoughts - should I increase bubble count or reduce flow rate to drop ph even lower ?

Thanks in advance
Andrew

HuduVudu · Nov 9, 2020

@jda can help

SinCityRee4r · Nov 9, 2020

andrewb70 said:
Hi I have a Reef Octo Calcium reactor running with ARM Extra Corse media and appear to be getting CO2 building up inside the reactor. There is a lot of bubbles being recirculated.

Tank Volume 120 Gallons mostly SPS frags - 1 year old
Ph inside reactor 6.3
Effluent dKh 13.2
Effluent Flow Rate 30ml/min
30 bubbles per minute
Tank dKh steady at 8.5 - which I am happy with of course.

Seems odd that the Effluent dKh is so low at 6.3ph and the CO2 is not being absorbed ??

Any thoughts - should I increase bubble count or reduce flow rate to drop ph even lower ?

Thanks in advance
Andrew

I read somewhere that the ARM media had a lower PH melt rate than usual 6.5 for standard media. Do a google on the ARM media

andrewb70 · Nov 9, 2020

Thanks for replies.

The reactor holds just 1 gallon of ARM Extra Coarse I was wondering if that larger media would be better suited to much larger reactors.

jda · Nov 9, 2020

You should not have built up co2 in the reactor. If you do, you are adding too much or you have a leak that is letting air in.

I don't get into pH in a reactor since it is fool gold, but if it is at 6.3, then this is too low and can turn your media to mush. If you really were at 6.3 pH, then the effluent dKh should be more than 13... something is not adding up.

Do not rule out an air leak. If you need to test for this, turn the co2 off, let all of the air out and see if it comes back. I had one once that was really stubborn and it took me a while to find it. You can also have air bubbles in the sump where the intake comes from. Check it all out and don't assume anything.

andrewb70 · Nov 10, 2020

jda said:
You should not have built up co2 in the reactor. If you do, you are adding too much or you have a leak that is letting air in.

I don't get into pH in a reactor since it is fool gold, but if it is at 6.3, then this is too low and can turn your media to mush. If you really were at 6.3 pH, then the effluent dKh should be more than 13... something is not adding up.

Do not rule out an air leak. If you need to test for this, turn the co2 off, let all of the air out and see if it comes back. I had one once that was really stubborn and it took me a while to find it. You can also have air bubbles in the sump where the intake comes from. Check it all out and don't assume anything.

Thanks for this. I did this test a couple of weeks back but am running it again now just to be sure - I set it to do so 5 hours ago I turned off CO2 supply - so far no air in the reactor but will wait another day or so. Will report back tomorrow

andrewb70 · Nov 11, 2020

Hi been over 24 hours now and no excess air in the reactor - from reading other experiences on the forums it's looking like the ARM Coarse is just not absorbing the CO2 at ph 6.2 and the excess is building up. May look to try another Media perhaps a smaller grain size

jda · Nov 11, 2020

I use ARM course right now. It dissolves. Forget the pH and either turn the co2 up or drips down (not both) until you get an effluent dKh of 20-25. Wait overnight to test. Might be a good idea to check your alk test kit since it is likely that either it, or your pH probe/monitor, is inaccurate.

andrewb70 · Nov 11, 2020

jda said:
I use ARM course right now. It dissolves. Forget the pH and either turn the co2 up or drips down (not both) until you get an effluent dKh of 20-25. Wait overnight to test. Might be a good idea to check your alk test kit since it is likely that either it, or your pH probe/monitor, is inaccurate.

Thanks for your input jda - I will follow your advice

andrewb70 · Nov 25, 2020

OK still having build up of CO2/Air in the reactor and finding it difficult to get Effluent dKH to anything above 20. What I have been doing is pushing water from the sump into the reactor with the Kamoer. So I have now shifted that to pulling (as per Coravlue Youtube Vid) which it does very well - however the water level in the reactor only gets to the height of the outlet and no higher even after 5 hours of pumping 120ml per minute via Kamoer. It needs to go higher to create some pressure as the CO2 recirc line will just pump air around. I thought the Varios2 pump would offer some priming capability and create some pressure inside the reactor - I was wrong. The Reactor inlet on the pump is about 20 inches above the sump water line see pic. So I guess 2 options left to feed reactor - 1. T off the return pump pipe. 2. Feed with MaxiJet 1200 or better - I feel there is a need to create some pressure in the reactor - thoughts ?

Attachments

jda · Nov 25, 2020

Expunge all of the air. Turn the co2 off. See if the reactor fills back up again. If so, then you have a leak which can drive you crazy trying to find it.

andrewb70 · Nov 25, 2020

JDA - thanks for your reply - the CO2 is not on at the moment as i've switched over to pulling with the Kamoer last night. I would like to expunge the air but other than taking the lid off and filling with water to the top not sure how to. I need some more water to be pumped in.

jda · Nov 25, 2020

Won't it escape through the pH probe hole or the other two top fitting? One of them is for air and the other is for effluent output.

Can you post which model you have and I can look?

andrewb70 · Nov 25, 2020

Reef Octopus CR140 - one is for CO2 Recirc

jda · Nov 25, 2020

That co2 recirc will also recirc the air and not allow it to escape - it does not know air from co2 from shineola. I don't know what to do if you want to use that. I would just have a john guest ball valve on that one to let the air out and tune it so that co2 does not build up and need recirculated. The kaomer, maxijet or T should be able to fill up that reactor and push all of the air out if you open one of those up.

Coralvue might have a plan on how to handle this that is better than what I am typing.

My apologies if I am misunderstanding all of that.

andrewb70 · Nov 25, 2020

@jda - will put a powerhead feed pump on later and see how that goes and let you know - then perhaps a T-Line at the weekend thanks again

The Opinionated Reefer · Mar 24, 2021

It is perfectly normal to get some build-up of c02 in calcium reactors especially when you are running it with a low throughput high dkh effluent. This is made even worse when using ARM extra course which needs a PH of around 6 to melt properly. This is now made from calcite and will not turn to mush easily. Also, I don't understand why people keep recommending this large chunk sized media. You would be much better with smaller grain size media, this will provide much more surface area for the co2 to be absorbed and result in less gas build-up and a lower internal ph to get the desired effluent strength. The ideal size for me is the seachem reef react medium grade or Aquamedic Hydrocarbon medium.

You will notice that all the new fancy automatic calcium reactors like Dastco and Deltec Twintech have degassing cycles that run once or twice a day to vent this build up gas. The only way to really avoid this with a normal reactor is to run it with a high throughput so that most of the excess gas works its way out of the effluent line but this comes with its own set of disadvantages.