Ro/Di water isn't the best thing for plants at all. If at all possible just use regular tap water. Other wise your looking at tons of $$$$ to get all the minerals and this and thats that the plants AND fish need. RO/DI water is generally best used when it's in combo with tap water. IF you do use just RO/DI water let me know cuz there is a lot of things I'd need to look up for you (like what minerals and other stuff you'd need to put back into the water) and some other stuff. That will take a lot of time to do. Not to mention where'd you get all the stuff from. Headache central for all of us m8. I wouldn't mind doing it, it would take a lot of time to dig around for. I'm not all that knowledgeable on Ro/DI water. I know some but not a lot. Just something to think about. Let me know what your plans are once you read this so I know what direction to go in lending a hand if you wish it.
Rose