GSPs can be moody- mine turn dark when resting and brighten back up when the lights go on. Watch for having a belly after eating that goes away fast and white poo. I like Ultra CurePX for parasites- don't put it in the tank- they won't eat it. Soak the food in a few drops. Treat usually for 4-5 days. Ultra Cure is available at Pet Supplies Plus (east coast) and I think I got it at Petco too (may have been PetSmart). Not expensive and works pretty well.