I need help tuning my CA reactor please

[BlackTip]

Geo 624, Masterflix peristaltic pump, Carbon Doser, and lab grade Neptune PH probe connected to Apex. All equipment are brand new. Pump and PH probe are calibrated and read accurately. Plumping is checked and double checked, and there is no air or water leak.

Problem:
Gas accumulation in the reactor. I thought it was air, but now I am almost sure it is co2

What I did:
Before starting each scenario, I plead as much air as possible from the reactor. I set the feeding pump at 100 ml a minute for couple of hours, turn the circulating pump on for couple of hours, gently shake the reactor few times to dislodge air bubbles. When the reactor is almost empty from gas, I turn on the carbon doser.


I've been experimenting and working with Geo's customer support for over a week now. I am gonna give you the skinny.

First setup:
Feeding pump at 30 bpm
Carbon doser at 1 bubble per 3 seconds at 2 psi
After 24 hours:
PH inside the reactor is 6.83
Effluent alkalinity is 20 dkh

Second setup:
Feeding pump at 40 bpm
Carbon doser at 1 bubble per 3 seconds at 3 psi
After 24 hours:
PH inside reactor is 6.58
Effluent alkalinity is 30 dkh
There is a lot of gas bubbles inside the reactor.

I don't understand why there is access co2 gas in the reactor, while the ph is only 6.58? Shouldn't the access co2 decrease the PH?

What can I do to have the effluent at 35+ dkh without access gas in the reactor?

Thanks,

[slief]

Originally Posted by BlackTip

Geo 624, Masterflix peristaltic pump, Carbon Doser, and lab grade Neptune PH probe connected to Apex. All equipment are brand new. Pump and PH probe are calibrated and read accurately. Plumping is checked and double checked, and there is no air or water leak.

Problem:
Gas accumulation in the reactor. I thought it was air, but now I am almost sure it is co2

What I did:
Before starting each scenario, I plead as much air as possible from the reactor. I set the feeding pump at 100 ml a minute for couple of hours, turn the circulating pump on for couple of hours, gently shake the reactor few times to dislodge air bubbles. When the reactor is almost empty from gas, I turn on the carbon doser.


I've been experimenting and working with Geo's customer support for over a week now. I am gonna give you the skinny.

First setup:
Feeding pump at 30 bpm
Carbon doser at 1 bubble per 3 seconds at 2 psi
After 24 hours:
PH inside the reactor is 6.83
Effluent alkalinity is 20 dkh

Second setup:
Feeding pump at 40 bpm
Carbon doser at 1 bubble per 3 seconds at 3 psi
After 24 hours:
PH inside reactor is 6.58
Effluent alkalinity is 30 dkh
There is a lot of gas bubbles inside the reactor.

I don't understand why there is access co2 gas in the reactor, while the ph is only 6.58? Shouldn't the access co2 decrease the PH?

What can I do to have the effluent at 35+ dkh without access gas in the reactor?

Thanks,

I'd bet it's not excess Co2 although I do think your rates are high. I run 24mlm/min flow rate via my Masterflex and 1 bubble ever 5-6 seconds at 3 psi to maintain 6.65 ph in the reactor. I would slow the Co2 rate down and see if that helps.

As a side note, I have run into issues with my Geo 818 getting excess air in it. I tore it apart a couple weeks ago. I removed every threaded fitting on it and replaced the Teflon tape with Oatey Great White pipe dope. This includes the places where the tubing connects as well as the fittings on the pump. Every single threaded fitting was removed and revealed using the pipe dope. I also tightened the screws on the circulation pumps volute. I pulled the uniseal at the bottom of the reactor, boiled it and coated it with silicone grease where it meets the reactor as well as where the pipe goes through it. I have absolutely no air bubbles in my reactor now.

[BlackTip]

Originally Posted by slief

I'd bet it's not excess Co2 although I do think your rates are high. I run 24mlm/min flow rate via my Masterflex and 1 bubble ever 5-6 seconds at 3 psi to maintain 6.65 ph in the reactor. I would slow the Co2 rate down and see if that helps.

As a side note, I have run into issues with my Geo 818 getting excess air in it. I tore it apart a couple weeks ago. I removed every threaded fitting on it and replaced the Teflon tape with Oatey Great White pipe dope. This includes the places where the tubing connects as well as the fittings on the pump. Every single threaded fitting was removed and revealed using the pipe dope. I also tightened the screws on the circulation pumps volute. I pulled the uniseal at the bottom of the reactor, boiled it and coated it with silicone grease where it meets the reactor as well as where the pipe goes through it. I have absolutely no air bubbles in my reactor now.

Thanks, as always, for your help.

I started very slow at 2 psi. The PH was 6.8, and the effluent alkalinity was 16 dkh. Those values didn't make a dent in my tank demand.

My tank need about 2 dkh a day. By my calculation, and I am not a math wiz, I'll need to replace 30g a day at 30dkh, which translate to 80 ml a minute. (Total water volume is 350g). Is this correct?

What is your effluent alkalinity?

Hypothetically, if I am dosing too much CO2, wouldn't the access CO2 reduces the reactor PH instead of circulating around?

[slief]

Originally Posted by BlackTip

Thanks, as always, for your help.

I started very slow at 2 psi. The PH was 6.8, and the effluent alkalinity was 16 dkh. Those values didn't make a dent in my tank demand.

My tank need about 2 dkh a day. By my calculation, and I am not a math wiz, I'll need to replace 30g a day at 30dkh, which translate to 80 ml a minute. (Total water volume is 350g). Is this correct?

What is your effluent alkalinity?

Hypothetically, if I am dosing too much CO2, wouldn't the access CO2 reduces the reactor PH instead of circulating around?

I have never looked at my effluent alkalinity. If my tank alk is high, I increase the reactor pH. If my tank alk is low, I decrease the reactor pH and increase the flow very slightly. That said, my parameters don't really waiver.

As to your question about dosing too much Co2, in theory yes. More Co2 = lower pH in the reactor. There is a point that the media will turn to mush but that is around the 6.5 range depending on the media.

[BlackTip]

Originally Posted by slief

As to your question about dosing too much Co2, in theory yes. More Co2 = lower pH in the reactor. There is a point that the media will turn to mush but that is around the 6.5 range depending on the media.

How could it be possible, then, that I have access co2 in the reactor while the PH is never less than 6.6? I am using Reborn media.

I am just trying to understand, because all of the literature I read says increase co2 dosing to lower ph and decrease it to increase ph.

[outy]

You don't have excess Co2 if the PH is to high. but 6.6 seems low to me, your close to the mush level.


I run high effluent and 100bpm and use no electronics just to keep up with my tanks demands.

In time you will get an idea of effluent and bubble rates just by eye.


You said you "turn the circulating pump on for couple of hours" you do know this pump stays on 24 hours a day and is never supposed to be shut off?????????

[BlackTip]

Originally Posted by outy

You don't have excess Co2 if the PH is to high. but 6.6 seems low to me, your close to the mush level.


I run high effluent and 100bpm and use no electronics just to keep up with my tanks demands.

In time you will get an idea of effluent and bubble rates just by eye.


You said you "turn the circulating pump on for couple of hours" you do know this pump stays on 24 hours a day and is never supposed to be shut off?????????

I am using coarse media 'Reborn'. All of the info I cam across states that coarse media needs lower ph.

I turned the circulating pump for two hours prior to introducing CO2 to flush any air/gases out. I know this runs for 24 hours.

[outy]

Originally Posted by BlackTip

All of the info I cam across states that coarse media needs lower ph.
.

Then you have 2 options

turn effluent down which will lower ph

or increase bpm


A large bubble up top of the chamber is common.

[BlackTip]

Originally Posted by outy

Then you have 2 options

turn effluent down which will lower ph

or increase bpm


A large bubble up top of the chamber is common.

I don't have a large bubble on top. What I have is constant small and large size bubbles circulating in the reactor. The circulating pump constantly makes a crunching sound due to air/gas entering the pump. The amount of air/gas increases with the run time.

[hkgar]

Here is some helpful info re setting up and tuning a reactor.

http://reef.diesyst.com/reactor/reactor.html

[outy]

Originally Posted by BlackTip

I don't have a large bubble on top. What I have is constant small and large size bubbles circulating in the reactor. The circulating pump constantly makes a crunching sound due to air/gas entering the pump. The amount of air/gas increases with the run time.

Again you only have those 2 options I provided if it is not sucking air from a leak.

The only other possibility is that you should let it break in.


I'm running the geo 618 on 250g volume and my recirc pump is silent at 100bpm at the lowest amount

[slief]

Did you buy this reactor new?? If not, don't assume you have excess co2. As I said above, reseal every fitting on the reactor as well as those on the pump. The recirculating pump will suck air if there is a leak on the inlet side. If your Masterflex is pulling through the reactor and not pushing, a leak will draw air from any number of places. Remove any Teflon tape and reseal with paste. Tighten the screws on the front of the pump. Get some silicone lubricant and reseal the uniseal to the body and the pipe. Use some silicone lubricant on the lid gasket as well. I have chased down this same issue and resealing every thing fixed the issue. Heck, even if your reactor is new, this could still be the root cause.

Once you have gone through and resealed all fittings, then we can start jumping to conclusions. If you do have excess Co2 in your reactor, as outy said, you have 2 options. Decrease the Co2 rate or increase your effluent rate because for that to be the case, you are pumping Co2 in faster than you are moving water through the reactor and oversaturating the water with Co2 which is virtually impossible given your reactor pH. I am almost 100% certain you have a leak either on the reactor plumbing, the masterflex lines or the circulation pump. That or you are pulling water into the reactor from an area with microbubbles.