Greg's 75g

[gregzz4]

My RO system has put me through the ringer lately ...

I changed the prefilter this last week, and after doing so, I heard it gurgling
Turns out it's been back-siphoning from the day I installed it, but I never caught it until now
Each time I've turned it on I've thought the purging noise I hear is just that, purging. After 11 months you'd think I would have spotted this
NOT

After the prefilter change I finally spotted the issue
The system has been sucking air in as it de-pressurizes and has been doing so as far as to drain half of my carbon canister
This is a concern as;
1 - An RO system should always be kept pressurized to protect the RO membrane
I can't fully explain this part, but I believe the theory behind it is solid

2 - Air entering the system will allow aerobic bacteria to multiply in the canisters

Now, there are tannins in our local water, so worrying about bacteria in my RO system is a waste of time, but it brought some other things to light. The one main thing is;
I've had crud in my ATO tank since day one and always thought it was from some kind of contamination. Turns out I was right

Apparently it's from the tannins in our local water, and no amount of filtering is going to help me as it's biological
I'm OK with this. At least I now know where it's coming from
I'll clean out my ATO tank every now and then, and I'll live with it

After hours and hours of online researching, multiple PMs with 11purewater, and finally a 45min phone call with him, I started to feel like I was on the right path to solving my issue

So, the problem was;
After my RO drum was full, the float valve would shut off and the waste water would stop. Nothing abnormal about that. Release the pressure from the float valve, such as using some water, and the system would back-siphon through the waste line until the Carbon canister was only half full. This is an issue as bacteria can grow in there with air

Sooooo, after many hours of testing, multiple PMs, and a much-needed phone call, I was convinced to butcher my RO system and start over

Right now I'll give a big shout out of thanks to Andy for all his help with my issues
Thanks Andy You da man

Looks like the problem is solved bud, with the addition of a valve on the permeate line even though the initial test failed
I don't understand why yet, but maybe you and I will figure it out after I send you my test notes ....

For those of you looking for pics, I started with this



I removed all of this



And I ended up with this



There will be some DI parts posted for sale after I finish this post

The system was butchered as we thought there may have been some air being introduced to the system as the water pressure dropped. Water can push against a seal and you'll have no external leaks, but remove the pressure, and air can enter through a seal as the vacuum of the pressure dropping is equalizing with atmospheric air

Long story short, I added a manual valve between my RO system and my holding tank, and all is good
Plus, of course, all of the removal of the 25 fittings I didn't need with their 50 o-rings - any 1 of which could have been a potential leak