I recently did a fun DIY project and wanted to share in case it inspires others. Marc Levenson mentioned a friend showed him a DIY degassing chamber during one of his live streams. His friend explained his home uses a well which can have excess CO2 in the water. CO2 will expire the resin we use in our RODI units. I’m on a well, make a lot of RODI, and noticed I was also going through resin rather quickly.
You can test for excess CO2 by taking a water sample and measuring the PH. Next you leave the water sample alone for 24-48 hours to “gas off” and measure the PH again. If the PH goes up you likely had CO2 in the water that gassed off. (Note - in my case I did this test three times but only saw the PH go up once.) Despite my inconclusive results I decide to give it a try.
You have a few options to solve this problem. You can use CO2 absorbing media (expensive), you can let the water “gas off” in an open container for 24-48 hours before running it through your resin (free but adds a step and container), or you can try to build an inline degasser. I found several other reefers who had attempted to create DIY degassing chambers like the one below.
I wanted my degasser to run inline with the source water and not have to worry about overflows (issue with the above design). This design is very simple but does require a booster pump. It was three easy steps:
I added a float value to a 5 gallon bucket and ran my source water into the bucket.
I added a powerful air pump and air stones into the 5 gallon bucket to help gas off excess CO2.
I ran an RODI from the bucket into my booster pump.
The air pump is loud when it runs but provides a lot of air. Here is what the degasser looks like when it is running:
Finished product with the lid installed to avoid contamination:
I make a lot of RODI water and was spending in excess of $250 of resin a year. This has saved 4-5x the amount of resin I was using so it quickly paid for itself. If you try to make a degasser be sure the share!