^what he said.
test your water, do a 50% change, test again. if the ammonia and nitrite levels are not under .25, do another water change and maybe another until they are. do this daily. ammonia levels under .25 will still be enough for the bacteria to feed and grow, but not enough to damage your fish. most of us on this site recommend the liquid tests kits. the initial cost can be a little steep, but they are much more accurate than test strips and last for much longer so in the long run the investment is worth it.
you will still have to do water changes once you are cycled to get rid of the buildup of nitrates, which is the final product of the bacteria. 20% twice a week should be good. keep the temperature of the new water the same as the tank, and remember to use dechlorinator.
also, do you have a clawed frog or an african dwarf frog? the clawed ones get big and mean and messy, and aren't really recommended for a community tank.
oh, and don't get advice from your Petco anymore. by telling you not to mess with the water, they are keeping their fingers crossed that your fish die from ammonia poisoning and you will have to go back there to buy replacements.
what kind of algae eater do you have? if you have a pleco, return it and get 1 or 2 otoclinus cats (quite small and effective). you will still have to feed them algae chips b/c they will eat all the algae. i doubt you have much anyway since the tank is so new. most plecos available are the common kind. small and cute in the store, they will eventually get about 2 feet long.
the cloudiness (aside from cycling) may also have some roots in overfeeding. one pinch once or twice a day, and half of an algae chip for the algae eater, more if it eats it fairly quickly.
I apologize if you know a lot of this already, but i don't know how much you know, so i wanted to cover a lot.