I've been using my Spectrapure MaxCap 90 since July 2022. My input water TDS is usually 115-130, output after membrane is always 2 after flushing and letting it run for a few minutes (often starts around 17 and goes down), and after DI1 is 0, then 0 after DI2. I have not changed the prefilters or Di's since July. All items are Spectrapure and not knockoffs. I use a Smart Buddie RODI booster so pressure is always at 90psi. So last week I moved my RODI system from upstairs to the basement. Everything seemed fine. I made some more topoff water following the same process as always and the results were the same as always. I have the Smart Buddie flush the membrane 2 or 3 times and then run with a valve shut out of the membrane to divert water until it's at 2 TDS from the membrane. I also have a flow valve after the 1st DI as it will spit out higher (20-30 TDS) for 20-30 seconds. Once that's back to 0, I send the water to the last DI and it's still 0 as always.
Today, my membrane TDS would not go to 2 and it has stayed hovering between 3 and 6 TDS and mostly 5 or 6. It's always gone down to 2 within 5 minutes. I've tested with my hand TDS meter without the Buddie running to confirm that out of the membrane is indeed fluctuating between 3 and 6 TDS. I know for some 6 TDS out of the membrane might not be bad ,but for my setup it's out of the ordinary to have 95% rejection rate. I would figure even if the water in the basement has something in it that upstairs didn't, the 115-130 TDS going into the membrane is the same as always. Can any of you think of a reason for this sudden change after only 7 months? It's not like the basement water is any different than what's upstairs as it's all coming into the house from the same single pipe and total TDS has remained the same of source water. I'm going to buy new pre-filters but could the membrane be going bad already? I don't do that many water changes at all and have only a 65 gallon aquarium. Thanks for any help! I HATE buying random things trying to fix the unknown, but here I go again! ha.
Today, my membrane TDS would not go to 2 and it has stayed hovering between 3 and 6 TDS and mostly 5 or 6. It's always gone down to 2 within 5 minutes. I've tested with my hand TDS meter without the Buddie running to confirm that out of the membrane is indeed fluctuating between 3 and 6 TDS. I know for some 6 TDS out of the membrane might not be bad ,but for my setup it's out of the ordinary to have 95% rejection rate. I would figure even if the water in the basement has something in it that upstairs didn't, the 115-130 TDS going into the membrane is the same as always. Can any of you think of a reason for this sudden change after only 7 months? It's not like the basement water is any different than what's upstairs as it's all coming into the house from the same single pipe and total TDS has remained the same of source water. I'm going to buy new pre-filters but could the membrane be going bad already? I don't do that many water changes at all and have only a 65 gallon aquarium. Thanks for any help! I HATE buying random things trying to fix the unknown, but here I go again! ha.