I used to keep a reef aquarium (haha, semantic irony) and I had a pretty high-grade RO/DI filter that I used due to all of the sensitive marine life that I kept. However it has been several years since my reefkeeping days and I still have my RO/DI unit. I know that using a RO filter on tap water is somewhat common among growers to remove all the crap in tap water, but I was wondering if there was any detrimental aspect to using both reverse osmosis and deionization to filter the water I give to my plants? I have read that drinking deionized water is not good for people. Could this also be the case for MJ plants? My filter always put out pretty much pure water. I would always get something less than 5 on my TDS meter, and usually zero. Would such pure water be an advantage over just RO filtration or would the complete lack of ions have a negative effect on my plants?
Take a glass of DI and spit in it... Measure the TDSs. Take some more DI and add nutes.,, Measure the TDSs now. It's no longer DI once its watered down. Take the same DI water and add it to the reef tank........ Pour it on dirt...... get my point? You can just use RO. No need to use DI water, but they will be fine.