silvertip shark catfish

Question
QUESTION: i bought 2 silvertips in 3 days my water was checked an its normal i have salt in the tank i have a betta an 2 tiger barbs and a frog i like this fish why is it dying on me?

ANSWER: Hi Mike,
Catfish and other fish that are scale-less do not like aquarium salt in the tank.  You dont need salt.  Many hobbyists think you absolutely need it because it makes their fish more healthier or better by providing electrolytes, when actually they do perfectly fine without it.  The only time you need to use salt is when you are trying to remove a disease such as ich or external parasites.  Also, adding salt will allow those diseases to gradually build an immunity to it and so the heat and salt treatment and salt-based medications will not work.
-Matt-

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QUESTION: i also heard that they need to be in a school because he didnt eat any food i have the right food for them sinking shrimp an its swimming was very crazy untill he died why do silvertip not last long in my tank i heard they get sick easily but i had 3 to die on me in to mths should i continue to try to care an make a home for this catfish?? also my barb i had for 3 days jumped out the water an killed hit the tank cover an died whats that about i bought him the same when i bought the shark?

ANSWER: Salt harms scaleless fish like catfish.  Might be the reason they died.  If a fish tries to jump out, it means they do not like the water and something about the quality is off.  They jump out in search of new or better water.  In a healthy tank fill all the way to the rims, 99% of the time fish still would not jump out.  Is this a new setup?  If it is a new setup, your ammonia is probably causing them to die.  Ammonia intoxication is because you do not have the necessary beneficial bacteria to break it down.  Bacteria takes time to grow.  Its a process called the Nitrogen Cycle.  
-Matt-

---------- FOLLOW-UP ----------

QUESTION: No my tank has been setup since march. I have had a lil problem at first
for bout 2mths but its been okay since then could my rocks be harmful I
have changed everything except the rocks. They are fake rocks should I
get live rocks?  

Answer
I dont believe it is the rocks that are the problem.  Live rock is only for marine tanks.  What are the readings of ammonia, nitrite, and nitrate?  Most pet stores offer free testing but they are WITH strips.  Test strips are inaccurate and should not be used.  It needs to be done with liquid testing such as from the brand API like the API Master freshwater test kit.  If you havent bought this already, it is greatly suggested.  It greatly narrows down the possibilities of the deaths because 90% of the fish deaths are from water quality.  
-Matt-