I've been preparing my irrigation water with reverse osmosis pressurized water for a few weeks now, and my plants don't smell like weeds anymore.

What kind of water you use is generally dictated by the water have accessible. Oppm Pure H2O at room temp sits perfectly @ a pH of 7. Distillation: Boils water, collects steam (pure H₂O), leaving minerals/contaminants behind (energy-intensive). Removes nearly all minerals, creating neutral, "flat" tasting water (e.g., 0 µS/cm conductivity). RO: Uses pressure to push water through a semi-permeable membrane, filtering out contaminants (less energy, but wastes water). Removes many impurities but often retains some minerals or adds them back with a post-filter, offering a cleaner taste and healthier profile. RO removes more contaminants but can miss some viruses, while distillation removes almost everything but can leave volatile compounds, with remineralization often recommended for both. Hard water provides beneficial minerals (calcium, magnesium) but can cause mineral buildup and pH issues; softened water lacks these, but replacing them with sodium can create harmful salt buildup, damaging roots and preventing water absorption, making natural soft water (like rain) often best, while softened water is generally harmful due to sodium, and hard water needs management. Pick your poison based on whatever. Worry less about type of water and more how fast the water cycles through your setup. 95-99% of daytime water use during photosynthesis is cooling and transpiration related the other 1% of water is split for its hydrogen. Using oxygenated water and water with increased molecular hydrogen concentrations, (hydrogen-rich water) (HRW) can be highly beneficial for plants. hydrogen nanobubble water (HNW), acts as a signaling molecule and antioxidant within plant cells. It is crucial to distinguish molecular hydrogen (H2) from hydrogen peroxide (H2O2). Good old tap water does the job just fine, I like to add 1g of ascorbic acid and let oxygenate for around 24 hours, will remove chlorine and chloramine from tap water almost instantly. Yes plants do like a tiny little bit of chlorine when growing but chlorine left in water with organic matter will quickly become nasty. When chloramine is left in water with organic matter, it reacts to form various disinfection by-products (DBPs), particularly nitrogen-containing DBPs (N-DBPs). Not good. chloramine (and chlorine) in tap water can be harmful to plants, especially in hydroponics, as it damages beneficial soil microbes, disrupts nutrient absorption, and can cause root/leaf issues, though soil buffers some effects; however, letting water sit or using filters (like for aquariums) can remove chloramine for safer plant use, as it's more stable than chlorine. Know thy enemy. Goodluck Mr Blackman.