Ro/di Help

[Zombiex]

I have been having alot of issues with algae and have been evaluating my entire system trying to eliminate possible causes. I tested my water today and its reading 112ppm for my rodi water. I have a bypass i use for making drinking that bypasses the 2 di stages. That water reads 4 ppm. I have a puratek system. I have added a second membrane and 2nd di aswell as the di bypass. Can anyone give insight as to the proper order of stages and if I have membranes proper. Currently as far as i can tell order goes.
Intake-pre filter and pressure with then goes to carbon then out to membrane then waste from membrane goes to second membrane. Both products are tied together then go to a t with 2 shut off. One directly to a water bottle for drinking then another to the 2 stages of di. Di is due to be changed but would depleted di add tds?

 

[Pistol]

yes exhausted resin will leach back the tds, start there

 

[Pistol]

Also, dual membranes require 80 psi to work properly and you should have a pressure tank if you're using drinking water.

 

[Zombiex]

My booster pump runs at 100 psi. I only use it to fill 5 gallon culligan jugs. Its not hooked up to a tap or anything.

 

[Pistol]

Ahh yes, that works.

 

[Salty Cracker]

What's the TDS of your source water? You shouldn't need 2 membranes unless you have crazy high TDS.

Swap out your DI resin for new stuff (make sure the canister is the right way up!), and then re-test. Also, do you have a flush option?

 

[Zombiex]

I run 2 membranes for reduced waste and faster production. The ro system automatically flushes its self. I will check source tds

 

[Salty Cracker]

I run 2 membranes for reduced waste and faster production. The ro system automatically flushes its self. I will check source tds

I looked into this too, as I have 3 ro/di setups sitting here... and I was thinking about the massive amount of waste water that would be produced by the two membranes, so I went with 2 DI stages instead. I'm about 130TDS into the system, and 4TDS into the RO/DI. The first DI canister should last quite a while with that kind of output numbers, and the second one should last over a year. My waste water TDS is usually around 250, and it makes a LOT of waste water (my water bill is high enough).

 

[cica]

....... and I was thinking about the massive amount of waste water that would be produced by the two membranes........

Actually the two membrane system produces less waste water then the one membrane system. the second membrane is being fed from the waste water of the first membrane, squeezing out more "clean water" from the waste water so reducing the amount of the total waste water.
I tried it ones but didn't like that the second membrane works much harder, since the water on its input is much higher tds. Also the output from the second membrane had much higher tds (if I remember correctly, around 8-10tds) so I just went back to the one membrane system.
My waste water now is going into the outdoor fishpond to make up for the evaporation.