Strange RO/DI TDS Issue

[ocboat]

I have a Spectrapure Max Cap 180 gpd ro/di system that is having a strange issue concerning the final tds of the water.  Water entering the system is around 45 tds, post ro membrane it is registering zero tds, also zero tds after first di cartride but 5 tds after final polishing di cartridge.  This lasts for about 5 minutes as it will eventually lower to zero tds.  I recently changed both the sediment and carbon block and the mega max cap di cartridges are about a year old but have very little use and very low tds that has passed through them. I can't figure out how zero tds entering it could raise up to 5 tds while it is not in use.  It's very similar to the membrane tds creep that eventually lowers as water flows through it.  I've switched the tds meter probes around and it stays the same. Has anyone else experienced this or have any ideas?  Thanks. 

The unit I have: https://spectrapure.com/collections/water-systems/products/mega-maxcap-180-gpd-5-stage-manual-flush-ro-di-system-mmc-rodi-180-10-mf

[Micah]

I had a similar issue with one of my TDS probes.  Pull it out of the john guest fitting and give the contacts a good cleaning with something that won't corrode the metal contacts and give them a quick wipe down.    That fixed it for me.  YMMV.

[Parzifal]

Just make sure when you put the sensor back in the fitting it is oriented so the water passes through them like a goalpost. 

[ocboat]

Thanks.  I'll try these suggestions tomorrow.