Columbian shark

Question
I really have faith on this cause this is my last resource! I bought a columbian shark about 4 days ago the place i bought it from said that it ate a lot and actually i could tell by it's belly, but once i brought it back home it hasn't been eating i bought a 14 gallon tank my columbian shark isn't that big for me to buy a bigger tank, but i do plan to buy a 30 gallon tank in the future ! My tank has other tropical fishes with him my columbian shark isn't aggressive
so it hasn't killed any other of my fishes. I tried feeding him pellets,flakes,bloodworms and i really don't see him eating and i truly am getting worried at this point i called the store that i bought him from and they said they fed him flakes, but he doesn't eat mine also i called this store and asked them and they told me it was adapting that it would eventually eat to go buy bloodworms so i did but i don't see him eating i put him isolated in this smaller tank to see if he would eat by himself but it didn't so i don't know what to do anymore he's still active swimming around playing with the bubbles and all i really don't know what to do at this point or what i'm doing wrong ! i really don't want my columbian shark to die, but i don't know what to do anymore at this point if you could please help me give me some answers should i be worried or maybe try some other foods i don't know it's been 4 days and i haven't seen him eat when i feed all my other fishes he just keeps swimming so i hope you can help me out i truly would appreciate it cause pretty much this is my last resource other then that i would just have to watch and see and hope for the best. Thanks for taking your time to read this and i hope to hear from you really soon.

Lesly.

Answer
Lesly,
I would think the main problem is due to him being in a fresh water tank. These guys are brackish water fish as juveniles, and full salt water fish as adults. Most pet stores have the wrong information for this fish. Even though he is not too big, the minimum size tank he should be in right now is 75 gallons. This shark (cat) can grow to 20 inches or more. Depending on the size of the other fish, the Columbia Shark will eat small fish once it get big enough. They usually eat just about anything you put in the tank. I am thinking he is having problems because his water is wrong. Also, make sure his water is heated between 75 and 80 degrees.