What type of water should I keep my fish in? Water from the sink or something? And how often should I change it?
Most tap water is fine to use, you must treat out the chlorine that cities use to clean the water. You also must let the water sit for 24-48 hours to get to room temp. I would suggest that you consult vet for more help.
Tap is ok. And change it every 2 weeks
Tap is good, you just need to remove the chlorine.