Most fish may do this occasionally, but if they are all doing it you might have a problem. It could be a number of things, so I really can't help you w/out more info. Please post your ammonia, nitrites, and nitrates, any parasites you see (observe the fish very closely), any any other unusual behaviors.
Your ammonia and nitrite levels are toxic, and your nitrates are too high. :-\ In general, nitrates should be below 20 or 25, although with some more sensitive fish such as Otos it should be much lower. The ich sounds like it has just started, so your first priority should be getting down the nitrates. Hopefully your tank will finish cycling soon so your ammonia and nitrites go down too. The water change was a good idea, it probably helped lower your nitrates. The high levels of am., ni., and nitrate may very well be causing your fish to get sick due to stress.
When in doubt, do a water change! :
But anyway yeah water changes are always good if something's wrong. And I hate to tell you this but most things that say they speed up the cycle don't work. Won't hurt anything though.
It sounds like your tank never completed the cycle. I would recommend you test your water every day and do 30% water changes daily until those numbers for ammonia and nitrites read -0- and the nitrates remain steady at <10........Once these readings are at the optimal levels you can go back to doing your weekly water changes. Changing the water will without a doubt provide relief for your fish.