Spring water, Filtered water, or distilled?

[sepgundamrg]

Very true, however, keep in mind that the requirements of fish are very different from amphibians in all aspects. Water chemistry that is appropriate for soft water fish like discus, or hard water fish like cichlids can be very harmful to both anura and caudates alike. Also, in the case of many fish, the substrate used and the method of treating the water is what makes it suitable for the fish.

Substrate generally doesn't matter unless you're keeping something like corydoras catfish that requires a sandy substrate. I all acknowledge that water requirements for amphibians is different then that of fish, but I felt that I should add that ro-di water does not adversely affect fish, if anything it is healthier than regular de-chlorinated tap water.