calcium reactor effluent ph tuning question

[shoelevy]

hi guys.

recently i bought a korallin C1501 along with american pinpt ph monitor. Ca R is filled with ARM media.

as i understand from reading, ph of effluent should be 6.5-7.0.

but as i tuned over the past 3 days, i can't seem to get to that ph without excess co2 building up in the reactor.

here's what i've tried (all measurements taken at least 1 hr after tuning was done)

DRIP/min, bubbles/min, resultant ph

36 , 10 , 7.5 (not sure if excess co2 built up because never noticed)

36 , 15 , 7.5 (not sure if excess co2 built up because never noticed)

36 , 20 , 7.35 (excess co2 built up obvious)

28 , 12 , 7.3 (excess co2 built up obvious)

in order to lower the ph, i have to slow my drip rate and increase co2 count right?

but as seen, doing so results in excess co2 building up.

so i'm puzzled as to how i am supposed to lower ph when increasing bubble count or lowering drip rate already results in excess co2 building up and wasted.

hope to get some advice on this.

thanks

[weileong]

Increase the CO2 rate but give it more time like >12hrs for the chamber pH to reduce. 1hr is too fast and not realistic

[shoelevy]

i read from one of the threads in RC that 1 hr is ok...so some measurements were taken only 2-3hrs after tuning.sorry about that mistake

but i'm sure the 3rd and 4th readings were taken at least 12 hrs after the tuning was done (overnight and after coming back from work) and since there's already excess co2 building up, would you still advice me to up the co2 count weileong as the ph is at 7.3?

[weileong]

Is your pH monitor calibrated before use with fresh calibration solution? Suspect you're getting higher than actual pH reading.

If I remember corectly, I only get excess CO2 in my koralin clone when I push the pH below 6.5.

[shoelevy]

definitely fresh solutions weileong.

i used only the ones that came with the pinpt monitor...one is pinpt ph7 and the other ph4

[patrick123]

Not sure if this applies to you, but I used to have the same problem. Turned out that it was the piece of cotton wool undernealth the ARM preventig the CO2 from dissolving properly and ph could not be lowered.

After I replaced the cottom wool with a piece of plastic mesh, the problem went away. I can now lower to 6.5 without any CO2 buildup.

[shoelevy]

Not sure if this applies to you, but I used to have the same problem.  Turned out that it was the piece of cotton wool undernealth the ARM preventig the CO2 from dissolving properly and ph could not be lowered.

After I replaced the cottom wool with a piece of plastic mesh, the problem went away.  I can now lower to 6.5 without any CO2 buildup.

hi

thanks

i just checked and i see a blue sponge at the bottom...not sure if that's the problem though

oh, i've also noticed that there are bubbles of co2 forming in the cavities between ARM particles...and when i knock the CR alittle, the bubbles get dislodged and float up to the top and join the other excess co2.

does this information help in narrowing down the problem?

one more issue, the bubble coming from the counter seems to be not of consistent size and timing...sometimes, within a span of 10s, i get 3 bubbles, sometimes, within the same time span...no bubbles....and sometimes the bubbles are big...sometimes they're just so small...can anyone assist on this issue?

[weileong]

what regulator are you using?

[shoelevy]

i'm using D-D pinwheel regulator

http://www.eaquanature.com/store/product_i...roducts_id=1034

i heard its good? that's what the previous owner told me...yes...i bought the reactor and valve 2nd hand

actually, i read on RC that the pressure in the co2 bottle should read 950psi or at least 60bars.

mine is only 40bars...would that be the reason for the inconsistent bubble count?

[patrick123]

Hi,

Did you check to see if the bubble is indeed CO2? If the bubble get trap in the cavities of the ARM, this may be air instead of CO2. Did you properly release all the air in the CR and ensure there is no air bubble inside before you run the CR?

The fact that your PH is around 7.3 indicate that the CO2 has not been dissolved into the water in the CR. Is your CR airtight? The CR needs to be air tight to create a localized pressure to dissolve the CO2 into the water. You may want to check your blue sponge too. Is there any bubble trip below the blue sponge? This may indicate that the blue sponge is clogged.

Hope this helps.

[shoelevy]

Did you check to see if the bubble is indeed CO2?  If the bubble get trap in the cavities of the ARM, this may be air instead of CO2. Did you properly release all the air in the CR and ensure there is no air bubble inside before you run the CR?

i'm pretty sure the bubbles trapped are not air as i flushed the CR well and also ecause i dislodge them and they form again, and if i don't dislodge them, they grow even bigger and more in numbers...

Is your CR airtight? The CR needs to be air tight to create a localized pressure to dissolve the CO2 into the water.

i believe my CR is airtight because there are no water leaks.

but as to whether there is pressure or not, i believe don't have pressure...because i use gravity feed with little head-pressure as shown below. input 2nd compartment (green), output to third (red).

patrick123, you seem to imply that the co2 dissolves better under pressure? can clarify with me this pt? i used low pressure head cos i figured the drip rate is not fast

[patrick123]

I'm surprise that you are not using any pump to pump water into the CR. Does it work this way?

A good article to tune CR can be found in the following url:

http://reefkeeping.com/issues/2002-05/sh/feature/index.htm

Regards,

Patrick

[shoelevy]

I'm surprise that you are not using any pump to pump water into the CR. Does it work this way?

A good article to tune CR can be found in the following url:

http://reefkeeping.com/issues/2002-05/sh/feature/index.htm

Regards,

Patrick

i've read that article before..good one

I'm surprise that you are not using any pump to pump water into the CR.  Does it work this way?

if you mean whether it gets a flow through the reactor, then yes it works. also, see pt 9 in http://www.eaquanature.com/store/product_i...products_id=771

but if you're asking if this method makes the reactor work as it should, then no... and that's the reason for this thread.

can i ask once again regarding the matter of higher pressure in the reactor in relation to the solubility of the co2 gas? is there a relationship between the 2?

cos last i asked another reefer, he did give a slight mention on this matter

[weileong]

can i ask once again regarding the matter of higher pressure in the reactor in relation to the solubility of the co2 gas? is there a relationship between the 2?

Think of your soft drink and you'll get the answer

[shoelevy]

wa!

great weileong, i get it

i'll try and pressurise the Ca R and see how things go

will come back if i still face problems

thanks!

[patrick123]

Shoelevy,

You don't have to pressurize the CR. All you have to do is to bleach all the air in the CR, and ensure the lit is airtight and you are all set. The CO2 and the recirculation pump will do the rest and drop your ph.

You may want to connect a small T joint to your return pump and pump the water into the CR. Do you use any valve to control the drop of your water? Looking at the picture, may be air is leaking in through the outlet of the water return to sump and that's why your CR is not pressurated.

[shoelevy]

You may want to connect a small T joint to your return pump and pump the water into the CR.  Do you use any valve to control the drop of your water?

the reactor comes with the original valve to control flow at the outlet...but frankly, turn little bit only and you get a drastic change in drip rate

thanks for the tip on teeing off from the return pump but for now i'm trying out gravity feed from main tank which has much greater head pressure. will see if lack of pressure was what was giving me ph problem