mine was about 7-8in and you could see the food flying out his gills when he ate. if he ate a gold fish or something, scales would go EVERYWHERE out of his gills. there alot like oscars, very messy. maybe yours aint that bad.
but if the convicts are spitting food out and not eating what they spit out, that left over food could be the cause for the cloudyness, or it could just be over feeding. a crab or a catfish could fix that problem