sad day =[

[Fasht]

I never used any aged water on my setup and everything went well

[jibruno]

so when adding water to the tank, would it be smart to take water out of one of my other betta tanks and add that to the fry? or would that be a bad idea

[vilmarisv]

It would be a bad idea. There could be bacteria harnful to the fry. Adults can tolerate much wider range of water chemistry than fry can.
I agree that you don't need to cycle but the tank should be setup with plans at least a couple of days before you put the male in so you get some microfood growing.
I like doing it with my filter in so there's water movement, then I remove it before placing my pair.
As water changes go, you want to prepare your water also a couple of days before your water change and put a heater in the bucket to bring the water temp to the same as your spawning tank. If you use IAL in your spawning tank, you want to trow one in the bucket of water as well to bring the pH closer to the in the tank.

[callistra]

The aged water thing is probably due to very unstable ph. My ph fluctuates from close to 9 to under 7 over the course of 2-4 days. That's a ton and my strong bettas can survive but are stressed by it. Fry are more sensitive so probably not. Also as ammonia builds unstable phs swing even more towards the acidic side as "normal" water so that exasperates the issue even more. If you have stable water out of the tap then the aging process isn't as necessary so that's why some would have this experience and others not.