CJO
Valuable Member
A common issue among aquariasts is that their tank has a lower than desired pH. Many tanks commonly dip to a pH of 7.8 or even lower at night. Although, to the best of our knowledge, this isn't low enough to harm the inhabitants of your aquarium, it does slow down the growth of your corals.
The low pH is generally caused by excess carbon dioxide (CO2) in the system for various reasons. Common causes are the buildup of organics in a system, living in an energy efficient (fairly air-tight) house, and the use of a calcium reactor.
There are several ways of combating the problem. Many people grow macro algae in a refugium on an opposite light cycle from their main tank. The macro algae uses the CO2 during the light periods to create energy (remember photosynthesis?). Others dose with kalkwasser, which both adds calcium and alkalinity to the system and raises its pH. I was doing both of these things but was still having issues with low pH.
That's when I read about the use of a CO2 scrubber. What's a CO2 scrubber? Very simply, it's a container that holds soda lime. When you run air through the container, the soda lime binds with the CO2. This is commonly used in scuba diving rebreathers and in air lines for patients under anathesia.
In aquariums, it is very easy to connect the container to the air intake of your skimmer so that no extra carbon dioxide is going into your system. Most people who run CO2 scrubbers report a 0.2 to 0.3 increase in their average pH.
Parts/tools needed-
If you want to just buy a smaller amount, Eynonreefer sourced a 3 lb bag for $7.50 JOR553 - Soda Lime, 3 lb. bag in Anesthesia Products at Med-Vet International
Next, you need a container to hold the pellatized soda lime. You can use any clean, clear plastic container that you find around your house. I used an empty Gatorade container.
You need to drill small holes in one end of the container for the air to come in. Make sure that the holes are small enough that the soda lime can't fall through and make sure that there are enough of them so that the air is not overly restricted.
On the other end, drill a hole in the cap large enough so that the airline just fits. Push it in a little way and use superglue to temporarily hold it (superglue dries fast, but doesn't do a good job of adhereing to these plastics). Then, use silicon to seal both sides of the interface between the airline and the cap.
While you are waiting for the silicon to dry, you can decide where you want to put your container. If you have a large enough area under your tank, you might be able to just stand it up anywhere. My cabinet is fairly tight, so I used some screws and cut a plastic C-clamp in half to create a small holder for the container over the cabinet doors.
Once the glue is dry, fill the container with soda lime, put on the top and connect the other side of the airline to your skimmer's air intake.
I connected my CO2 scrubber a few weeks ago and the low point of my pH has gone from 7.8 up to 8.0.
Before CO2 Scrubber
After CO2 Scrubber
I hope this helps some people out. Please let me know if you have any questions or comments.
CJ
The low pH is generally caused by excess carbon dioxide (CO2) in the system for various reasons. Common causes are the buildup of organics in a system, living in an energy efficient (fairly air-tight) house, and the use of a calcium reactor.
There are several ways of combating the problem. Many people grow macro algae in a refugium on an opposite light cycle from their main tank. The macro algae uses the CO2 during the light periods to create energy (remember photosynthesis?). Others dose with kalkwasser, which both adds calcium and alkalinity to the system and raises its pH. I was doing both of these things but was still having issues with low pH.
That's when I read about the use of a CO2 scrubber. What's a CO2 scrubber? Very simply, it's a container that holds soda lime. When you run air through the container, the soda lime binds with the CO2. This is commonly used in scuba diving rebreathers and in air lines for patients under anathesia.
In aquariums, it is very easy to connect the container to the air intake of your skimmer so that no extra carbon dioxide is going into your system. Most people who run CO2 scrubbers report a 0.2 to 0.3 increase in their average pH.
Parts/tools needed-
- pelletized soda lime
- a clean, clear plastic container with cap
- drill
- drill bits
- super glue
- silicon
- airline tubing that fits your skimmer's air intake
- beer
- screws (optional)
- C-clamp (optional)
- hacksaw (optional)
If you want to just buy a smaller amount, Eynonreefer sourced a 3 lb bag for $7.50 JOR553 - Soda Lime, 3 lb. bag in Anesthesia Products at Med-Vet International
Next, you need a container to hold the pellatized soda lime. You can use any clean, clear plastic container that you find around your house. I used an empty Gatorade container.
You need to drill small holes in one end of the container for the air to come in. Make sure that the holes are small enough that the soda lime can't fall through and make sure that there are enough of them so that the air is not overly restricted.
On the other end, drill a hole in the cap large enough so that the airline just fits. Push it in a little way and use superglue to temporarily hold it (superglue dries fast, but doesn't do a good job of adhereing to these plastics). Then, use silicon to seal both sides of the interface between the airline and the cap.
While you are waiting for the silicon to dry, you can decide where you want to put your container. If you have a large enough area under your tank, you might be able to just stand it up anywhere. My cabinet is fairly tight, so I used some screws and cut a plastic C-clamp in half to create a small holder for the container over the cabinet doors.
Once the glue is dry, fill the container with soda lime, put on the top and connect the other side of the airline to your skimmer's air intake.
I connected my CO2 scrubber a few weeks ago and the low point of my pH has gone from 7.8 up to 8.0.
Before CO2 Scrubber
After CO2 Scrubber
I hope this helps some people out. Please let me know if you have any questions or comments.
CJ
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