For 30ft of wire, 14 AWG is fine for a 3/4 hp motor. If you're running it at 110V it's still file. If you want a bigger pump you should consider running them off of 230V. If you're already running 230V then 14 AWG will handle all the way up to a 2hp pump at a distance of 30'.

I have 10 AWG running from my breaker to my pool equipment for 230V plus a 14 AWG neutral if I need 110V over there.