New to the site and saltwater aquariums. I ha e a 20 gallon tank with live rock and sand. Had 2 clown fish and a six line wrasse. Everything was good for about a week. Came home from work today and one clown was dead and the wrasse is acting very sick. He's gasping and laying on the sand. I scooped him up in the net and when I let him go he took a nose dive straight back into the sand. I set up an emergency qt and put him in it. He is doing the same thing. All my water parameters are good but I did notice a lot more algae in the tank. Any ideas?