cloudy water is common during the cycling process and may or may not be the result of new substrate. if it is the substrate, have no fear, it will clear up soon. otherwise, keep up with the frequent water changes. are you testing the water's parameters? if so, what are you using? if not, buy a liquid test kit, not the strips, and test often in the beginning. 40-50% water changes daily or every other day until you see zeroes for nitrite and ammonia. anything other than zeroes means you are not cycled. will likely take about 6 weeks or so, give or take a week. unless....
best advice for you is to ask your fish store to squeeze out some bacteria from a sponge and dump it into your tank....also, if you know anyone with an established tank they could help you with this.
