Deffinately not, as stated, you will need to reconstitute the water with something like RO Right, to replace some of the heavier minerals, as RO water is 'dead' water.
Not being a fan of putting treatment in water anyway, I generally never use dechlorinator, i find aerating your water for 24 hours will do the job so much better and cheaper with less risk to your fish.
The only other problem you get with RO is that it can Ph crash (unless you use a buffer..ugghh..another chemical) Unless your trying to breed your fish, or have really sensitive fish, I'd forget RO water, and just let your fish adapt to your own water supply.