remember salt water is totally different than freshwater , things are done differently for a reason . any and all medication will leech into the rock rendering it useless ,if down the line you want to add coral they will most likely die off . inverts are very sensitive also they can and will be poisoned from the medication . this is why we never treat the main tank with any medication that's why a qt tank is needed.
I'm not here to steer you wrong if you chose to do different that's your choice.
Fish are like lifesavers
They come in different colors