Could you guys edit this list so that all the treatments have information on whether or not it is safe for inverts? I know it's a lot to ask, but I'd really appreciate it.
The long list I have supplied above didn't give any clue if it was invert safe. I would treat your sick fish in a separate tank whether you have 1 fish and a few shrimp or 30 fish and 1 shrimp.
Here are a few reasons a hospital tank is a MUST. To keep new fish from potentially spreading a disease or spreading parasites to your current stock. To quarantine sick fish in your current stock to prevent it from spreading the disease or parasite to others in your tank.
But the main reasons are the expense of treating a large volume of water with medication and over treating other fish that are not sick. You can pick up an extra filter, heater and a cheap plastic (I prefer hazy to clear 10 to 20 gallon NOT Steralite but a heavy duty Rubbermaid tub with a lid). You can then use the lid to cover the tub when it is empty and keep dust and such out. Also note it's cheaper to replace if the medication you are using will stain the tank. Make sure it is a thicker more heavy duty tub and not a real thin one. Clear/hazy allows you to see more of what's going on. Please note: the hang on filter may need a little persuasion to sit level as most tubs have a curved side.
Sick fish should be treated and kept in the quarantine tank for at least 2 weeks after the last sign of infection just to make sure the infection is not just dormant.
You should also treat new fish for parasites and once that is done give them medicated food to treat any bacterial infections that they may have BEFORE ever placing them in your main tank. 3 or 4 weeks total should be enough time to make sure the new fish are safe to add in your tank.
Failure to pre treat new fish or separate sick fish WILL become a costly problem and could possibly kill all your current stock. You put your fish into this situation it is YOUR responsibility to protect them and keep them safe!
If your main tank is contaminated and must be treated then removing plants, inverts, and any other live creatures that are not to be treated should be done (the quarantine tank can house them until the large tank is safe again). Do remember that scaleless fish like catfish can be killed just like your shrimp by some medications. Check your warnings and remove any fish, invert, plant that it does not say it's safe to treat or if it is not listed at all on the bottle.
Plants can normally be cleaned by a solution of Potassium Parmagate (It depends on the plant) or a real weak mixture of bleach and water but remember to declorinate the plants (weak plants will die and so will some sensitive others). Ultimately plants are normally cheaper to replace than a fishy friend that you have had for years.
Please remember to quarantine your new Plants and Inverts too! This includes but not limited to shrimps, clams, and snails. From everything I have read after a week any disease that can affect fish can harbor on the shell of Inverts and plants but will die if they don't get a host within a few days. So a week or two should be safe.
Take it from somebody who has spent over $500.00 in medication in less than a year from thinking that won't happen to me I just have a few fish in a large tank. Best of luck.