RODI problems

You can go to any hardware store and pick up some 1/4" line, a 1/4" tee and a 1/4" valve. I prefer push fittings as opposed to compression, just for how easy they are to put together. Make sure they are all plastic, don't let them talk you into brass compression fittings. Then just cut line between the RO membrane and the DI canister, install the tee, then reconnect the line. Then put the valve off the side of the tee so you can test between your RO membrane and DI. You'll need this so you can figure out the rejection rate of the membrane and determine if its at the end of its life or not.

 

You said you have a handheld TDS meter, yu have everything you need.

Get yourself a clear glass drinking water glass, wash it by hand in very hot water so it has no water spots, dishwasher soap residues or antispotting agents on it.

Draw a glass of tap water and insert your TDS meter, wait until the reading stabilizes and write it down. Next, very important, triple rinse the glass and the meter in RO/DI water or distilled water if you suspect your RO/DI has TDS.

Disconnect the 1/4" line leading from the RO membrane down to the DI canister at the DI end and fill the glass with RO only water if you don't have a DI bypass valve. Insert yur meter and let the reading stabilize and write it down. Triple rinse the meter and glass in RO/DI or distilled.

Reinstall the 1/4" line to the DI and draw a glass of RO/DI water, insert the meter, let it stabilize and write the TDS reading down, do a final triple rnse of the glass and meter, cap the meter and turn the glass upside down so it ctatys clean for next use.

What are the three TDS readings?

You need to know the TDS at all three points plus your water temperature, water pressure and waste ratio to troubleshoot your system. Without answering these questions No One can help you.

Disregard the answer someone provided about changing everything, chloramines, membranes lasting one year etc. They don't have their facts correct.

 

AZDR,

I've read others posts about TDS 'creep', where at first when it's on, it will have some creep/tds in the system, after it runs a 1/2g or so, it will read 0 again.

Your thoughts on that?

PS- I still haven't changed my filters or DI, and no water quality issues, knock on wood.

Todd

 

I'm ordering all new filters and a new membrane tomorrow and the flush kit. I didn't know you need to flush the system before and after you use it. I always put the hose in the jug and turned on the water.

 

Don't waste your money on a flush kit, it is not the same as a DI bypass valve which actually does do something.

ALL membranes suffer from TDS creep. What this is is when the system is sitting idle, the tap water on the untreated side is being pulled through the membrane to the treated side since the RO water is trying to get back to its natural "dirty" state and is wanting the TDS and contaminants on the other side. A "flush Kit" does not solve this issue sine it only flushes the waste side and the TDS creep is on the treated side. The DI bypass valve allows you to flush this high TDS water on the treated side to the drain before allowing it to go from the RO to the DI stage. Very different.

 

Thanks, I had known you were not a fan of flush valves, and that's the main reason why my RO/DI does not have one.