Hi Zany! Love your name!
Sphag moss can be tricky to keep the plant in. Phals don't like to completely dry out, but moss can be a bit much for them when they are outside of a greenhouse setting. Most of us change it to an orchid mix of pre-soaked bark, perlite, coconut husk, and a little charcoal.
I soak my roots really well, then let it drain out and not water again until I stick my finger way down in and feel that it's almost dry. If you mist it, mist in the morning and never let water stay around the leaves by evening.
I would also recommend orchid food for fertilizing every other watering. I'm not up on fish water, so I can't answer that one. Orchids need certain things that is provided in orchid fertilizer, so I would stick to that. Home Depot and places like that carry it and it's not expensive. Keep the plant in medium light, never alot of sun.
Good luck! Phals are wonderful plants that can live and bloom for you for many years! We often find bargain priced orchids here and there and it's like Christmas when we do!
There is a phal. culture sheet here on OB.
Again, welcome Zany!