A Tale of High Indoor CO2 and Declining pH

[MikeC]

Thanks Geraud I'm still looking around for a good valve
What made you decide to turn off your lights rather than just have the skimmer turn off until the pH dropped ?

 

[Geraud]

Mike, this is the one I am using: "Skinner Solenoid Valve MBD002". They are around 35$ used on eBay. (they are super expensive brand new, not worth it). I also got the 24V DC converter on eBay.

Well when I programmed that I was still using the original pump of my Tunze nano-skimmer, and since restarting it is always a "will it work this time?" The lights made more sense, plus I do not like being out of a skimmer for too long (light-wise I still keep my LED supplements on when the MH is shut down, and the corals do not seem stressed at all)

As a reference, here is the type of 3-way valves that exist. Note that only the multi-purpose is "direction-less".

http://www.allenair.com/Valve/Image/23wayvalve/2-3valva751D.gif

 

[Geraud]

I thought this could be interesting to show. I let my CO2 scrubber connected at night then stopped it yesterday morning. I then reconnected it at midnight, almost four hours after the MH went off.

The little oscillations you see at night are due to the KH dosing kicking in.

 

[jedimaster1138]

After my pH has been struggling to get out of the 7.80's the last week, I ordered some of that media from BRS as well. Let's compare notes.

Question for those running scrubbers - do you connect the scrubber tube to the main air intake of the skimmer, or the ozone port (assuming you have one on your skimmer)

 

[cybermeez]

I just finished hooking up my scrubber. After carbon dosing the pH is at 8.04. The lights are due to go off in about 45 minutes so we'll see what happens. The tank is 120g so this may take some time.

 

[cybermeez]

It's been 13 hours since setting up the CO2 scrubber and the pH is currently 7.98. Since the lights have been off it's hard to tell if the scrubber has made any difference. Guess I'll have to wait until tonight after work to find out.

If it isn't working, there may be one mitigating factor. The air intake on my skimmer takes 3/8 in tubing and the barbed connection on the scrubber is 1/4 in. I rigged up what I think is an air tight seal by inserting the small tube coming from the scrubber to the inside of the larger tube connected to the skimmer. I'm going to see if I can find a proper connection at Home Depot today. Even a 3/8 John Guest fitting should work.

More to come.

 

[lnevo]

Sounds like your pH is fine 7.98-8.04 is not bad

 

[Geraud]

Do you see the medium turning purplish right around the air intake? (not skimmer side) That is the easiest way to see if things are working properly.

 

[cybermeez]

It's definitely pulling air. I can hear it and a little bit of the media has begun to change color. It's either a matter of volume or efficiency.

I just put a John guest fitting on that is the appropriate size for the 3/8 tubing going to the skimmer. If any air was bypassing the cartridge, it isn't any more. I also shortened the tubing and it's now about 3 feet long.

So, I've addressed any potential efficiency issues and if things don't improve, it will come down to the volume of air that the skimmer can pull and the ambient CO2 in the room.

 

[MikeC]

Well my pH has not been able to get much past 8 and more times than not it was 7.6-7.8

1. I have two windows cracked open in my reef room and central AC.

2. I have great water surface agitation
(3 Mp40's and 2 Mp10's)

3. I dose Kalk.

Looks like it was time to try a DIY Co2 scrubber.

Lid Lock container

Sponge leftover from Mag 18

Drilled the bottom and sides 1/2 in holes

3/8 John guess fitting

Scrubber complete

I put it on line last night at 8:30 pm
pH was 7.94

It is now 6:00am the next morning and my pH is at 8.06

Yay! So far so good.
I will continue to monitor it and report back what it gets up to during the day.

 

[cybermeez]

Woke up this morning and the pH 7.95, lower than yesterday at the same time. So, it looks like this isn't working for me - at least not in its present configuration.

I'm going to try to increase the volume passing through the cartridge. This may prove problematic though because the skimmer is already foaming a lot and increasing the airflow may make the skimmate too liquid. It's already pretty thin. I'm open to any ideas.

I'll post some photos of my setup later today.

 

[Geraud]

MikeC, 8.6 before the lights went on? That's crazy, is your pH probe properly calibrated? Be very careful to not get it too high!

Cybermeez, I was going to suggest dialing up the air flow a bit. You should have to compared to running without, but not by a lot.

Can you post pictures of your own setup?

 

[lnevo]

Yeah, i was wondering the same thing about 8.6 and this is before lights on??? What is your target range?

 

[MikeC]

MikeC, 8.6 before the lights went on?

My bad I ment 8.06 sorry
I will edit first post

 

[cybermeez]

Cybermeez, I was going to suggest dialing up the air flow a bit. You should have to compared to running without, but not by a lot.

Can you post pictures of your own setup?

Photos below. I have the air flow wide open and the pH after 4 hours is 7.97. BTW that CO2 canister you see on the left is not in use so it's having no impact on the tank.

 

[Geraud]

Can you see if the purple color is "expanded" at the bottom of the container? Aka you want to make sure that the air is somewhat "spread" around.

What is the pH of your tank during the day?

 

[cybermeez]

The media is turning purple from the bottom up. During the day the pH has been running anywhere from 7.8 to just under 8.0. If I didn't dose with kalkwasser it would fall below 7.7.

 

[Geraud]

I re-read your initial post, and what could be happening is that since the CO2 in your apartment is so high, the surface agitation could actually counteract the benefits from the scrubber.

It looks like in general, you might want to do something (at the landlord level maybe) to not have such a high CO2 in there... maybe grow some plants?

 

[cybermeez]

I wonder, would moving my vortech pumps down deeper in the tank help?

 

[cybermeez]

Well, I've ordered a kalkwasser stirrer. I'm going to keep running the CO2 scrubber for the time being. I've been manually dosing with kalk twice a day and my Ca and Alk just tested at 490 and 12.4 respectively with the pH at 8.09.

The stirrer will will replace my 2 part dosing unless measurements indicate otherwise. To keep the Ca in solution I'm going to have to dose Mg pretty regularly if I have to keep running it on the high end of the spectrum.