We’ve got 4 RO/DI units, but one of them is killing the DI within 2-3 hours of use. That one is the Tucker RO/DI cart. We recently replaced the membranes in two of our units with the Axeon HF5. The prefilter is new. The ro membrane is removing approximently 92-93% of the tds from the tap, which usually ranges 350-450. So the DI has had water coming into it that has been between 30-45 tds. Works for just a couple hours, the the tds starts getting worse out of the DI, then it was going IN the DI housing. Starts creaping higher and higher till we can’t clean windows anymore. We’ve trying nuclear grade resin from a certain vendor, same result, some older resin we had from WCR, same result, brand new resin from WCR, same result.
The membrane seems to be working great in the tucker machine and in our wash it pro. I think we started having the issue before we swapped membranes, and it was the reason we changed the membrane.
Similarly, the DI in the Wash-it-pro has been doing it’s job just fine as well.
We’ve also swapped the DI canister itself, with a new canister
We are all scratching our heads, and it’s driving us up a wall and it continues to try to ruin our work days.
I thought the tds coming into the DI should be much lower, 10-15 range.
Are you using a pump? if the psi is too high that can cause issues. under 100 psi on the RO is the max mine can handle without issues.
When you say pure water, do you mean for the membrane, the di tank or for output?
Each membrane is rated for a certain psi.
The Axeon hf5 might be the best ultra low pressure membrane on the market. It’s rated for as low as 80 psi, but can handle up to 400. It runs more efficiently with MORE pressure.
On the other hand, you can run di tanks with too much pressure. Too much pressure may cause tunnels in the resin, and too high of gpm can cause the water to move through the tank/canister before it has enough time to “marinate” in the resin and “shed” the minerals.