If you reduce the feeding the ammonia should go down. The fish will be fine if they are only fed once a day or even once every couple of days.
Different corals will close up earlier if they aren't used to the light they are getting. eg: if they come from a low light area and get stuck under really bright lights it can take them a few weeks to get used to the extra light. During this time they will close up to reduce their time exposed to light and the associated photosynthetic activity in their cells. Poor water quality will also cause corals to close up but most or all of them should close up if that is the case.
If a shrimp or crab walks across them they will close and if a fish is picking at the coral it will close up.
It is impossible to say why the clownfish died. It might have been stressed out in the bag, or it might have had a disease, or it might be your tank. If the other fish are fine then it was probably stress from being in the bag. You want to get the fish home ASAP and keep them dark while they are travelling, use a carry bag to put them in. Once you get them home float the bag in the tank for about 30 minutes. During that time add half a cup of tank water to the bag every 5 minutes. At the end of 30 minutes pour the fish into the tank. You can pour them into another container and scoop them out so you don't add the shop water to your tank if you like.
The salt creep sounds normal. It is from airbubbles breaking on the surface. Little bits of salt and minerals get thrown onto the glass when the bubbles burst. This leaves behind the salt and over time it builds up. It is most common on opening or around the edges of the tank. Just wipe it off with a clean damp sponge.
Different corals will close up earlier if they aren't used to the light they are getting. eg: if they come from a low light area and get stuck under really bright lights it can take them a few weeks to get used to the extra light. During this time they will close up to reduce their time exposed to light and the associated photosynthetic activity in their cells. Poor water quality will also cause corals to close up but most or all of them should close up if that is the case.
If a shrimp or crab walks across them they will close and if a fish is picking at the coral it will close up.
It is impossible to say why the clownfish died. It might have been stressed out in the bag, or it might have had a disease, or it might be your tank. If the other fish are fine then it was probably stress from being in the bag. You want to get the fish home ASAP and keep them dark while they are travelling, use a carry bag to put them in. Once you get them home float the bag in the tank for about 30 minutes. During that time add half a cup of tank water to the bag every 5 minutes. At the end of 30 minutes pour the fish into the tank. You can pour them into another container and scoop them out so you don't add the shop water to your tank if you like.
The salt creep sounds normal. It is from airbubbles breaking on the surface. Little bits of salt and minerals get thrown onto the glass when the bubbles burst. This leaves behind the salt and over time it builds up. It is most common on opening or around the edges of the tank. Just wipe it off with a clean damp sponge.
