So I have a 45 gal tank. It has been setup for about 3 months. It has already gone threw its cycle. I'm new to this hobby. I have had about $300.00 of fish die in this tank over the past 2 months. 1 yellow tang 4 clown fish 2 lawnmower blennies 2 cardinals 1 fire shrimp Note: not all of the fish have been in the tank at the same time. 15 snails 5 hermit crabs I spent $300.00 on a brand new 6 stage RO/DI unit thinking that it might be the water. I have been doing a 5gal water change a week. I keep testing the system and all of the levels are fine. PH 8.2 Ammonia 0, Nitrates 0, Nitrites 0, Copper 0, Temp is set to 80, Salt 1.23 They get fed twice a day; The lights are on for about 9 hours. I am currently left with a small Yellow Tang, Cleaner Shrimp, Chocolate Chip Star fish, 3 Turbo Snails, 3 hermit crabs, If I can’t find out why the fish keep dying soon. I might not be keeping this hobby much longer. Does anyone have any idea or help that they can provide.