If you put vitamins, food, etc. into one tank, do you also have to put it in your second tank for it to work in both?
Thanks!

Yes, all items in the toolbox apply only to the tank you are currently looking at. You must feed the fish in each tank separately, for example. In addition, some chemicals will not affect a fish in the isolation tank, so if, for example, you're trying to cure a sick fish, make sure that it is in the main tank, not the isolation tank.

Thanks, Barbara!