Reverse osmosis

[Cinnup3x]

Is it really necessary to have a reverse osmosis filter for a hydroponic system?

 

[spyralout]

Is it really necessary to have a reverse osmosis filter for a hydroponic system?

Only if your tap water is high in PPM. The main thing in hydro is to try and keep pathogens at bay, which can be an absolute struggle.
Having RO water also helps you start with a "clean slate," allowing you room to dial in your nutrients to your liking. Hydro can be tricky if you start going over 800 PPM. Although doable, you'll start running into lockout issues.

 

[RollTheBones]

The trick with RO water is understanding that stripping all the salts also removes the natural PH buffer. So seemingly subtle treatment of RO water with lots of air-stones rather than some other aeration method will result in rapid ph excursions. Unnoticed, these sorts of things turn into severely stunned or dead plants. With hydro, you have to get into the science of water a bit more than coco or other neutral media.