is this better/ and sea monkeys

fyi, some brand sell 'sea monkeys' when in fact they are brine shrimp(artemia)
the package usually consists of eggs and crystals( aquarium salt)
the 'sea monkeys can like in relatively low salt almost brackish conditions.
while they may live with the 'magic crystals'
you can just as easily buy brine shrimp eggs(artemia) add aquarium salt and grow 'sea monkeys' plus it's probably cheaper..I raise them to feed BBS(baby brine shrimp) to fry.
as for copper safe..check the label my guess is it is probably chelated copper..this stuff will kill ich but it is also difficult to remove from the tank as the 'chelated' copper can stay in the tank at lethal doses(for ich and other parasites) for over 30 days..chelated copper is also lethal to invertebrates(shrimp etc)

from the sounds of it your tank is well on it's way to a cycle..as ammonia drops you will still need to monitor it and make sure you keep the nitrites in check.
 
salt is included in the "instant crystal" package, and you're supposed to use purified water because all necessary minerals are included in the packets. if you use tap water and you have copper pipes, the copper could kill them. i'm not saying you did it in purpose, but i'm saying it's not going to work out if you try it.
 
AquariaCentral.com