I just set up my 20g Landen AIO. I bought the live rock yesterday with corraline all over it, set up my tank and added it yesterday but when I woke up today it looks like a large portion of the corraline on top that isn’t covered by sand is dying off already. The guy at the aquarium shop said all I needed to do was add the saltwater I bought from the shop, put the rock in and that I don’t even need a heater yet. Also said I didn’t need to dose it with anything but when I woke up this morning the water is still cloudy although much less than before I added the sand, rock & water. Temp went from 85 degrees to 74 now this morning and the corraline is definitely dying off. Can someone tell me what I did wrong? Something tells me I should have went with my gut and added the beneficial bacteria and dosed some calcium once I set up my tank. Sounds like I may have made a few newbie mistakes too.