Well water in whole-house water filter turning green
You don't need to experiment with this system. What you have there is algae growth because you have opened up your well house to sunlight. This is a very common problem. Algae is every where, it is in the wind, all around you. Algae needs two things to grow, sunlight and water. You just supplied the sunlight. Eliminate the sunlight and you will not have any growth. I usually recommend to my clients that they make a boot out of insulation for there filter. Or you can simply replace your cartridge housing with a new one that is not clear. The clear ones are nice because you can see your filter and it indicates when to change. But, you already know that because of experience with when to change your filter out. So, Boot over the filter housing or change housings, problem solved.