No you don’t need salt in this tank. Sharks are actually cat fish in fresh water and should not have salt added to the tank.

In the quantity you would need to use salt as a preventative (which it really isn’t) would kill off your fish first. Salt actually interfears with a fish’s ability to process the water they absorb to keep their organs functioning properly. Keep the salt out.

What kind of fish do you have or plan to get. Most fish don’t need any salt, but if you have livebearers like guppies or mollies, or African cichlids, or brackish fish, these always do better if they have a little salt, like a tablespoon for every 5 gallons of water. Some fish like tetras and catfish can be sensitive to salt.

I’d say to look up the kinds of fish you have and see if they would like any salt.

Oh, and if this is a new tank, since you say you added biozyme, a little salt, about half of what I said above, will help while your tank is cycling. The salt protects the fish from nitrIte that builds up.

Is this the shark you have? They ABSOLUTELY need to have salt in their water!!! When they’re adults, they live in marine conditions!!! Maybe not while he’s small enough to fit in a 10 gallon, when he should just have at least a teaspoon per gallon, but soon. You do know these get over a foot long, right? Here’s a better website for taking care of these, but most places call them by their real name, Colombian sharks. That website was the first I could find that calls them silver-tipped. I think pet stores changed the name so people don’t know they are the same thing, and that they grow up to be monster fish and will need to be put in salt.

I don’t know if he’s going to get along with your other fish, either. Too bad you can’t remember what they are. But unless it’s an orange molly or out of a tank of Tanganyikan cichlids, it’s probably not going to like the amount of salt your shark is going to need in a few months.

If he’s what you have, please take him back. He’s going to be too big for the tank you have, and you will probably have to get a second tank for your other fish too. And while you’re there, find out what kind of fish your other ones are and look them up. It’s a good idea to do your own research on a fish before you buy it. They may not be a good idea for your 10 gallon, if they are cichlids. Some better choices could be smaller barbs and tetras, or guppies, or platies.

Unless you intend to keep marine fish (such as Clownfish, which are more difficult to keep than freshwater fish) or fish that require brackish conditions, then no, salt isn’t required and most tropical fish such as tetras won’t tolerate salt in the water. However some fish, such as mollies and other poecilids, actually appreciate a little salt in the water.

what sort of fish

if they are marine or brackish fish YES
if they are freshwater NO

why did you buy the fish and tank at the same time

some of the fish will probably die during the nitrogen cycle