So, after stripping down, cleaning and checking, I cannot see any rust on my RW4s or my MP10. Weird. I need to check heaters and return pump really, but given I will be transferring tanks soon, I think that can wait until then. I am going to do some heavy water changes in the meantime, but have removed the booster pump from my RO machine in case that was the thing leaching Zinc into it.
I did 20% change on the night before last with my refreshed RO machine. New sediment, carbon and DI. Went to pull some water off last night after removing the booster pump and checked TDS. 41 in..... 8 out. What the actual ####? So stressed out over that, knowing I had used that water for my change the day before and my RO top up, took me ages to get the DI pod off to see if it was pressed in properly, which it was. Then struggled to get it back on......... before realising I had it in the machine upside down, meaning it was being bypassed completely. Jesus wept Phil you moron.
Its like a slow trickle without the pump too, so throwing away 25l which took 4 hours to make did not make me happy. Hopefully, everything should be working better now. It's showing zero TDS at the moment. I'm going to carry on with water changes every other day of 20l and do another IPC test next month.