You're feeding them fine for guppies and swordtails. The cloudy look is probably fungus, explain to the fish store (they're usually pretty good arounf here at diagnosing disease), maybe a round of erythromycin is in order, could be velvet amongst other things. Ick is usually tiny flecks, a cloudy patch is usually fungal. If he's really rubbing that side, that would indicate ick as it itches the fish. Hmm, didn't realise fish itched until I re-read that outloud. Wish my head was a little clearer, lol, I'm sleepy.
