I am learning over the last 2 years that RO water is not a good idea for our plants. RO is so efficient that it removes good nutrients like calcium, magnesium, iron, potassium, zinc, and many others. Plants become micronutrient defficient.

I now feel that if a person uses RO water they need to replace ALL micronutrients. And because mixes and ferts expect those micronutrients to be present in the water supply, the plants can show many different forms of stress, the most prevelent one causing an appearance of Rust Fungus. Treatment of rust fungus involves expense......... Treatment of RO micronutrient shortages is simple ONCE IDENTIFIED, tap water.

I suspect that distilled water may also cause issues, I don't know if the micronutes follow the water in distillation, I think not tho.

Also noted, is that this really does not show until in flower.

SO thumbs down to RO in my garden and tumbs up to tap water that has evaporated the chloramines.
WashougalWonder Reviewed by WashougalWonder on . Reverse Osmosis can cause issues I am learning over the last 2 years that RO water is not a good idea for our plants. RO is so efficient that it removes good nutrients like calcium, magnesium, iron, potassium, zinc, and many others. Plants become micronutrient defficient. I now feel that if a person uses RO water they need to replace ALL micronutrients. And because mixes and ferts expect those micronutrients to be present in the water supply, the plants can show many different forms of stress, the most prevelent one Rating: 5