[Darkblade48]

Is there any particular reason you are using RO/DI water (perhaps keeping sensitive livestock)?

If not, I would just use tap water.

RO/DI water has the disadvantage that it has essentially no minerals, so you will need to remineralize it (in addition to fertilizing your plants, which you would need to do in any case).

 

[Sluggo]

Is this a whole-house system, or are there bathtub taps, etc. that aren't filtered? There are various mixes to re-constitute pure RO water (RO Right, Equilibrium), but I have tried them and wound up with some funky algaes. RO water may need additional buffering to prevent pH swings. If you have very hard tap water, you can experiment with mixing RO and straight tap water until you get the conditions you want.

 

[lamiskool]

oh the system is only for part of the house and is used for drinking water. from the looks of it and researching a little more I think I will stick with regular tap water. The water where I live (milpitas, CA) is not extremly hard or anything and is actually quite "safe." I guess I might just mix in a little of the RO/DI water with the regular water when I do water change to make it a little softer for my fish (they are all fairly hardy fish). Thanks!