CO2 advice
 

I have too much Co2 in my water. It is keeping the PH around 7.8-8.02.
I do have a Cal reactor hooked up to this system, but it rarely comes on due to the low Ph. I have it set to come on at 8.01 and off at 8
I know it is a CO2 issue because I turned off the Skimmer this AM to feed the corals, and the Ph dropped quickly to 7.78. Now that the skimmer is back on it has come up to 7.89 in just under an hour. The lights are still not on. I have a 50 gallon tank with a sump under the stand, which is fully enclosed other than the back, which is up against a wall with about a 4" gap. Here are my questions that I am looking for advice on.
1- With the skimmer (BK 180) in that enclosed area, wouldn't any CO2 that it removes just get sucked back in through the air intake? How can I avoid this. How long of an intake air hose can I add before it no longer adds enough air to the skimmer?
2- If I were to add a air stone to the sump which is very crowded, where would I put for most effectiveness, and wouldn't I just have the same issue as above?
3- I know that Kalk will remove Co2, but I don't want the Alk or Cal to be raised anymore than they are right now. Alk= 8DkH and Cal = 450. I am running Zeovit so I must keep the Alk low.
4- Ideally, I would like the Ph to run between 8.1 and 8.2
Does anyone have any suggestions?

Thank you

pH
 

Is the drip line from your reactor above the water line? Keep it 4"-6" above to allow for some of the co2 to dissipate in the air. Your reactor should not change the pH of your system, just one idea.

Yes it is. about 4" I would say.

Hi Marty

What is your PH after your lights have been on for 4 hours or more.

My Ph falls to between 7.89 and 7.92 during the night and then climes to between 8.2 and 8.3 during the lighting cycle. This is not a swing that should cause any problems.

Some people try to compensate for this by running the lights on their sump on a reverse cycle.

I am running the PH in my CA reactor at between 6.5 and 6.6. I then run the reactor effluent through a second CA stage with no CO2 added. This helps raise the PH before the effluent returns to the system. It is only a partial fix.

Tom

Marty
MOST reef aquarists have difficulty keeping their pH in the 8-8.3 range due to a variety of factors. Your cal rx is one factor but i don't think its the primary factor. The breakdown of organics in your system is another factors and so is the photosynthesis cycle that occurs during day/night time cycle. Your ph is quite normal for reef systems. You can add 8.3 kH buffers to your system but that will change your alk levels. I recommend using kalk in all your top off water via a kalk reactor if that can fit in your system. I was able to keep my pH in the 8-8.3 range when using this method. And if you wish to maintain 8 dkh, then adjust your calcium reactor accordingly if your dkh begins to creep up too high.

[quote=martym;371726]I have too much Co2 in my water. It is keeping the PH around 7.8-8.02.
I do have a Cal reactor hooked up to this system, but it rarely comes on due to the low Ph. I have it set to come on at 8.01 and off at 8

marty why would you set the reactor to come on at 8.01 and off at 8?

What kinda Ca rx do you run, how many lines feed back to your tank?

My Ca rx has 2 lines back to the tank however I only use 1. It goes into a plastic cup where the pinpoint moniter sits. I have set my Ca rx to come on at 6.8 and off at 6.5, maybe I didnt read it correct from above but if you set your reactor at 8ish it wont melt the calcium, anyhow just get a plastic cup that you can zap strap to your return line submerge the monitor in that and set your ph to the same setting I have above then the return line to drip into the cup at a rate of 2 or 1 per sec. By that rate the drips falling into your tank will evap some of the ph and it flows at such a slow rate that the ph in your tank should hold 8 if it doesn't then you can try to put some ph up or kalk drip but you shouldn't need to before I had a stream of effulent into my tank I noticed the ph drop to 7.8 now with the slower drips it stays at 8 or just abit above gl.


Chris

a pH of 7 is neutral so the Calc Reactor wouldn't work well if the pH is above 7. The water may not be acidic enough to dissolve the media. Have you tested the Ca in your water over time to see if the Ca is being replenished by the Reactor or is it being replenished by water changes? I run my reactor at 6.5 to 7.0 pH and maintain Ca at around 450 ppm.

I have been running my tank at around 7.9-8.3 for over a year and though not optimal, it's been pretty good. The drop in pH at night in normal and one option to negate that is to run a reverse light cycle refugium with some form of algae/plant to take up the CO2 and release O2 into the water at night.

I used to have ph at around 7.8 to 8.0 because of my calcium reactor but now after adding cheato to my 20 gallon sump and keeping the lights on 24 hours a day, my ph now varies between 8.1 at night and 8.3 daytime. I can see the change on my ph meter within an hour of turning the lights on. I have cheato about the size of 2 basketballs in the sump and it really worked well for me.

Tom- There isn't that much of a swing when the lights go off. Drops down to around 7.8 by 5am.
Chin- I have been thinking about a Kalk RX and a Auto top off. Just thought that the 2 combined would be over kill. I like the Cal rx due to it's simplicity.
Tang Daddy- I have a PM cal rx. There is one line going into the tank. The rx is set to the tank Ph. When the MD Ph drops below 8 the Rx turns off, but when the MD Ph goes above 8.01, then the rx comes back on. the effluent out of the rx is 6.7 when it is on. I have the drip into thank around 1.5 drops per second.

So it sounds like I shouldn't worry about it then. Thanks everyone for your help.

I've never heard of anyone running their Ca reactor this way. If the reactor rarely comes on, how are you meeting your Ca/Alk demand?