first off stop feeding feeders it is very bad for them and will not grow very big to say like how big mine is and they can even kill your P's with infection, secondly do a water change at 30% every week and always use the conditioner. You shouldn't be doing the huge amount of water change because it could be throwing your water params off and making the tank go through a mini cycle that can cause water cloudiness. Check your water params. Also you should get rid of that substrate and go with some darker natural colors, it will make your P's much more happy and active as well bring out more of their colors , I have black sand in mine and they love it.
