questions/help

Hello any organic soil growers still starting seeds in rock wool cubes? Wondering if i could just use pure R/0 water the pH is a perfect neutral (7) but i was taught to soak rock wool in pH between 5.5/6. But i wish not to alter the water with any chemical pH down or up.

Using R/O water would be perfectly fine. I use tap water for everything in my organic grow and never had problems, so I'm sure you will be fine.

When you are germinating you should try to ph the water down to 6.0 when using rockwool cubes but since there's no roots formed yet 7.0 ph directly from your tap should not hurt them over the short term. If you want an easy way to lower the ph just add a few drops of lemon juice. You really only need to ph the water if the cube is not yet transplanted into soil.
Once there are roots emerging from the cube you can transplant to an organic starter mix & then the soil ph will offset the ph of your tap water so you shouldn't need to ph your water after that. It takes a week or more for a ph imbalance to have an effect on your plants so you could prolly get away without ph-ing the water at all if you get it in some ph balanced dirt real quick.

All i can say is Awesome Mr. Drysift, very well worded and explained. I will definately adhere to your advisement, thanks for the knowledge and input.