I have had to deal with burning through my di resin like crazy over the past few years being on well water. I would use almost a resin refill in a little over 40-50 gallons of water. The only explanation was co2 in my well water. I knew I needed to rid the co2 before going into my resin. I decided to have a holding tank with straight well water on a float system. In that tank I have an airpump with an airstone running 24/7 which vents off the co2. I have a small 24 volt submersible pump in that tank that pumps to my ro booster pump. From there on out the system works normally like a standard ro/di filter system. My booster pump is turned on and off with a pressure switch that is very common with booster pumps. I use the power supply that turns on the main booster pump to also power up the submersible pump that is in the holding tank, that is why I went with a 24 volt submersible pump. I have made several 30 gallons worth of water and only used about 1 in of resin in the cartridge for each water change. So I feel this has been a great addition to my water system. Should save a lot of money over the years in the costs of di resin. Hope this can help someone who is fighting co2 issues.
Jeff
Jeff