Low pH issues?? Make your own CO2 scrubber!!

I'm a stickler for stability, and you might be too. Are you experiencing some pretty dynamic and erratic pH swings? I've seen pH in my system as...
  1. So let's talk about why you're here and why I decided to write this. From time to time I've had low pH issues, and I suppose you have too, it can be frustrating. I for one am not the type of person to chase numbers , but when you can do something about it, why not!? This is where I decided to look into why I was having low pH issues.


    As you can see on this Apex graph my pH wasn't horrible but low and erratic. Sound familiar??

    First off I'll say that I'm no scientist, or chemist so if your checking this article out for scientific terms, etc.... I'm not your guy. I'm just a hobbyist and a business owner that has a lot of experience, and I've been keeping tanks on and off for most of my life.

    So why be concerned at all with pH?? I'm a stickler for stability, and you might be too. Are you experiencing some pretty dynamic and erratic pH swings? I've seen pH in my system as low as 7.5 and never got higher than 8.1 . So my search was on searching for causes. After searching throughout R2R, I did a couple of tests and determined that CO2 was the culprit. Yes, even us old timers look for pointers. LOL

    Now what to do about it?? Well I tried increasing surface agitation with more pumps and pointed them at the surface for gas exchange. Have you tried that?? As a matter of fact, if I had added anymore agitation I would be blowing water out of the tank!

    The end result of that was a lot of excessive salt spray and not much else. So now what do we do?? Well, my next step was a little more drastic, but was an easy job--I decided to drill a hole in the side of my house and run a line to my skimmer for an outside source of fresh air.







    In pictures 2-8 you can see some of that process I captured. Here is a link to the complete thread.

    Skimmer pH bump

    I'd also like to add a link to another great article by @jsker !


    You see, if I open the windows up in my home, my pH would go up, but like a lot of folks, we can't possibly keep our homes open all the time. Sound familiar?? LOL Being from the Midwest, we deal with extremes. One day it's 100° with 90% humidity, and the next it can be snowing.

    So after running the line, I did get a nice little pH bump. It had worked, but like most people I wanted to push a little more.


    In pictures 9-10 you can see I did get a nice little pH bump.

    The next and final step was to make my own CO2 scrubber. It's not as hard to do as you might think. As a matter of fact, I made 2 with existing stuff I had laying around. The only thing I intentionally purchased to do this was SODA LIME . You can purchase it from a welding supply store or you can also get it from www.Bulkreefsupply.com



    In pictures 11-13 you can see I used an old GFO reactor and placed a sponge on the bottom inside the reactor, filled it with the soda-lime and placed the top back on it.

    In picture 13 you can see how the media (soda-lime) changes color as it is exhausted. This was about 1 month of full 24 hour use.

    The inlet side of the reactor is hooked to the incoming outside air line and the other end goes to the skimmer intake. Shown in figure 14.


    After having a great deal of success, with using soda lime I decided to put to use some older equipment I had laying around.

    In pictures 15-19 you'll see an empty salt bucket I had so I drilled some small holes in the bottom and lined the inside with some plastic screen material. Then pour in about 1 inch of soda lime and place your air pump in the bucket and run the airlines and power cord out the top. Then hookup the dual airlines to air-stones and placed them inside your sump. In picture 19 you'll see how my pH climbed very nicely!






    In conclusion, you can see now my pH has gone up from an average of 7.8 to about 8.2. Its also much more stable and predictable. I hope you enjoyed this and have success with some of these ideas. As winter nears, we will all be inside more and the dreaded pH drop may come and pay you a visit, but you'll be prepared!

    Happy Reefing!

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