CO2 advice

[martym]

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

[The Codfather]

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.

[martym]

Yes it is. about 4" I would say.

[Tom R]

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

[Chin_Lee]

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.

[tang daddy]

[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

[slakker]

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.

[wil0311]

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.

[martym]

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.

[untamed]

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'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?

[martym]

Thats the issue I'm having. How else do you keep the Ph in the MD from dropping, if the Rx is running all the time?

[tang daddy]

technically if your rx comes on at 6.7 and goes off at 8 then either you have 2 ph monitors or you have set it wrong!!

the ph set for your monitor should kick off at ph 6-6.4 and on at 6.5-6.8, that is my understanding and as for your md it should hold at ph 7.8-8.3 with your lights coming on and off.

Mostly everyone on here will agree or have the same standards in mind, if you already have kalk dripping into your tank it should balance it out.

really it's up to you but if your reactor is not holding a 6-6.8ph then the calcium cannot melt therefore not meeting the demands of your tank.

[dstasiuk]

My PH level runs at 7.8-7.9 w Cal reactor and dripping Kalk at night. I gave up worrying about it and let it sit there - no ill effects are observable after months in that range.

One thing that helped a little was running my effluent into my skimmer - seems to blow off more CO2 before it hits the main tank.

You may also want to make sure you are refreshing the air in your room - my ph goes up abit if the house is empty, and drops abit with more bodies. Opening a window near the tank helps stabilize those swings...

[martym]

Tang Daddy- That is basically how it is running. I do have 2 monitors. But for me the controller is in the main tank. The monitor is in the effluent just before it drips into the tank. So when the tank is above 8.01 the Rx turns on. The effluent then drops down to 6.7 and remains there until the ph in the tank drops below 8.0.
Yesterday for an example, I managed to leave the window in the room where the aquarium is open all day. The Rx came on at around 10am and was still running when I went to bed at 9:30pm. The Ph in the MD is at 7.9 this am (5:30am) So it is running, and maintaining the values that I'm after, for the most part. My Alk does dip down to 7DkH just before my bi-weekly WC. My concern is the Ph in the main display had dropped to below 7.8, which is a bad thing. I was hoping that I could keep it up a bit higher than that.

[StirCrazy]

for 5 years my PH was always 7.8, no problems. Add a Kalk reactor and if all it took was to open a window you need to ventalate that room.

On my system I ran the Ca Rx 24/7 and the kalk Rx on my top off water.

Steve

[untamed]

You are letting the pH of your display tank run your calcium reactor, which does not make any sense to me. It is not a tool designed to maintain pH....it is a tool designed to deliver Ca/Alk requirements. There is not a demand relationship between Ca/Alk and pH.

Here's how my reactor works... The pH probe is in the Ca Reactor chamber and the controller keeps that chamber at pH of 6.4 by adding Co2 when necessary. That is low enough to dissolve the media. The effluent from that reactor then goes through a 2nd stage where further reaction takes place. By the time the effluent comes out of the 2nd stage, the pH is up to 7.6. Optimally, it would be perfect if that effluent got back up to pH of 8.

I also have a pH probe in my display tank. It provides entertainment...but nothing else.

[martym]

My RX has only one chamber
here is how Randy Homles set his up. This is from is article on Reef Central.
"A more elaborate method is to connect the solenoid valve to a pH controller and place the pH probe into the calcium reactor. The valve then switches the CO2 on and off to maintain a target pH within the reactor. I use a similar method. The pH probe is placed in the tank, and switches off the CO2 flow to the calcium reactor only when the pH in the tank has dropped too low (e.g. pH 7.8 or lower).

This is how I run it, but I try not to let the PH get that low.

[Chin_Lee]

Marty
Randy's method and your method are very different. He is using the ph controller to control the pH inside a calcium reactor whereas you are using a ph controller to minimize the pH drop in your display tank.

I wouldn't be too concerned about the pH in the tank. 7.8 isn't really bad at all as this is quite normal for many reefers that do not does kalk. Use kalk to raise the pH in your display tank via a kalk reactor on an auto topoff.

I would use the pH controller to control the pH inside the reactor only. As more effluent exits your calcium reactor, it will buffer the system and prevent it from going any lower than 7.6.

[martym]

Ok, I have now changed what I was doing. The controller is in the effluent, has the rx come on if the Ph is above 6.8 and shuts off if it goes below 6.4.
Thanks everyone for your help.

[untamed]

My RX has only one chamber
here is how Randy Homles set his up. This is from is article on Reef Central.
"A more elaborate method is to connect the solenoid valve to a pH controller and place the pH probe into the calcium reactor. The valve then switches the CO2 on and off to maintain a target pH within the reactor. I use a similar method. The pH probe is placed in the tank, and switches off the CO2 flow to the calcium reactor only when the pH in the tank has dropped too low (e.g. pH 7.8 or lower).

This is how I run it, but I try not to let the PH get that low.

I get it. Randy is using low-pH as an emergency shut off for the reactor (at tank ph 7.8). By setting your shut off as high as 8.0, you probably shut down the reactor for most of time that your lights are off.

[martym]

Yes that was happening. Then it would take a long time for the Ph to raise again. I have switched the way I'm doing it to what Tang Daddy suggested. I'm curious to see what happens with the Ph now

[untamed]

It will bounce up and down in a daily cycle controlled by your lights.