to add to this, river rocks can hold minerals that are not good for saltwater. dont know if scientifically it would really matter, but if normal rocks have certain minerals and metals in them, it could seriously harm saltwater fish. or at least, that is what ive heard from LFS before. i have also heard the same of the plastic gimmics leeching chemicals. i would definately get rid of those.im no expert but heres some of what i know, and dont take this wrong just typing fast and giving out my $0.02 haha first i would remove all that freshwater tank decor as it has plastics and other materials that the salt water will break down and leech chemicals into the water, second from reading the posts your tank is no where near ready for probably fish and especially coral, the tank might or might not have cycled already which is a big thing, salt water tanks are a giant tank that requires chemistry, those rounded river rocks offer little to no biological help,