Hi STB.
Silver Sharks are often also known as Bala sharks.
I've been keeping them for a few years now, and whilst I'm no expert, I have learnt a lot.
The short answer to you question is that no, they are not really that easy to keep.
The long answer starts here.
The first problem with them is that they are a nervous fish, and need to be kept in groups. You must have a good lid on the tank, and it should be positioned away from any major disturbances. Otherwise you will be retrieving your fish from the floor, or worse still, not retrieving it from the back of the tank.
Next problem is nitrAtes. They can be very sensitive to higher nitrAtes, so water quality really does need to be very good. Bearing in mind that as they get larger, they produce more and more waste.
Finally, as CS says, they will get big, and can reach 6-7 inches in just a couple of years, often only 18 months. And they swim fast. Personally I would say an 8 foot tank is the absolute minimum for an adult fish.
they are not a good beginners fish, and are not one you can drop in the tank and forget. I check my water quality twice a week, have spent over £1,000 on two tanks in 18 months, and will have to buy another one in the next 18. However, if you can give them the dedication they need, and the space, they are an extremely rewarding fish, that will provide you with hours of enjoyment.
Ian.
