This may be a bit of an odd question, but where I live, the well water is extremely bad. The amount of sulfer in the water makes it unusable for anything other than washing dishes and laundry. I had a chlorine injection system installed shortly after buying my home and it does a great job removing the odor. In 6 years I have not drank the water or cooked with the water, or let my pets drink it. It's disgusting to be honest.
I installed a reverse osmosis (RO) system that is now tapped in (using a saddle valve on the PVC) before my softener and my chlorine system, whereas up until recently, was AFTER both the softener and chlorine systems. This RO system will soon fill (I am still working on this) two 55 gallon potable water barrels to have on hand to top of my tanks after cleaning/partial water changes.
Previously(when the RO was installed after the softener and chlorine), I would disable my softener and chlorine system, and run the water until it stinks to make sure all the chlorine and treated water passes. I would then turn on my RO system to top off my tanks (125g and 180g tanks). This takes an incredibly long period of time. The RO system does roughly 5 gallons an hour optimally. I could need 30-50 gallons of water to top of the tank(s) after a quick cleaning, which means ~10 hours of having my softener and chlorine systems disabled. During this time, I can't take a shower, flush the toilet, run any water during this time, or else my house will smell of rotten flesh and rotten eggs. It's VERY inconvenient.
With the old setup (RO after the softener and chlorine), If I leave the softener and chlorine systems enabled, the RO water is very high in nitrates, ammonia, and basically the levels are bad enough to kill my fish. This just happened recently. I had 10+ freshwater fish die from a water change.
I want to know if my treated water could backflow into my RO system. I only thought of this after I tapped into the water just after the well pressure tank.
My water system is currently setup like this:
- Well to 27 gal pressure tank,
- pressure tank to chlorine system (pressure tank injected by a stenner pump),
- chlorine pressure tank to softener,
- then onto the house plumbing and hot water tank
The softener is after the chlorine system because previously, when the softener would run, my whole house would smell INCREDIBLY horrid(softener was before the chlorine). The place that installed a NEW softener(and also did my chlorine system) said it would have to be installed after the chlorine system to avoid this.
So now, for my RO system's water supply, I tapped into the main water line just after the well pressure tank thinking that since it was before the softener, chlorine, etc, it would be feeding my RO system with un-treated water. But after thinking about it, I am concerned that treated water could backflow into my RO system's intake.
I hope this makes sense. I've searched and searched and haven't been able to decide one way or another.
Sorry if my terminology is off, but I am not a plumber (you guys are WAY underpaid).