Black Moor and Black Shark

Question
I bought a Black Shark to go along with my Black Moor, Koi, and 2 algae eaters. He would hide behind a plant for a day. Then he began to chase around the black moor and I thought they were playing a game. Then when I woke up I came to check on them and the black moor had multiple bites in the tail and even a whole side of scales missing from his side. We immediately separated the black shark into a different tank. He had been OK with the other fish though. The black moor hasn't been acting different, but will he die without his scales on one side and bites in the tail? The pH level is 7.5. Also, the black shark won't eat. We feed them dried bloodworms and the other fish eat it. Should we feed him something different? Also we have a betta (separate tank)should we put the Black Shark in with him? Thank you.

Answer
Hi Mansa;

Black sharks are aggressive and territorial, often hiding and then chasing the other fish. They are also tropical fish that should be in a heated aquarium kept at 76f to 78f. Your koi and goldfish are cold water and should be kept in 72f or less so they just aren't compatible for that reason too. The shark will also tear up and probably kill your male betta because the shark is very fast and will be relentless in his pursuit of him.

To help your black moor heal, keep the tank very clean. Frequent water changes will lower the amount of naturally occuring infectious organisms such as fungi and bacteria that are always present in our tanks. Change 25% of the tank water at least every other day until the wounds close up and he shows signs of healing. Fresh clean water also boosts the immunity of your fish so he can fight off any infection that may still set in.

Also use two natural products to help him heal faster. Go to your local fish store and get aquarium salt and a product called "Melafix". Fish stores should have them. Use the melafix according to the label instructions and add 1/2 teaspoon of the aquarium salt per gallon of tank water. It's okay to keep making water changes during treatment with salt and melafix. Just do the 25% water change right before that  day's dosage. The melafix gets old in the tank after several hours, that's why it is added every day for a few days so don't worry that you are removing anything useful when you do the water changes.

The salt doesn't get old though stays in the water unless you actually replace the water so don't add a full dose every time you make a partial water change. Start by adding a first initial salt dosage of 1/2 teaspoon per gallon to the tank. Every time you make a 25% change, add back only enough salt to treat the replaced water. For instance, if you remove 2 gallons of water, add back one teaspoon of aquarium salt to the new 2 gallons of fresh water. This keeps the salt concentration the same all the time. Whenever adding salt to a tank, dissolve the proper salt dosage in some water in a separate container and then slowly pour the salted concentrate into the tank, or just dissolve it in the new water before pouring the new water in. Don't pour the salt or the salt solution into the filter though. It will kill some of the beneficial bacteria in the filter that keeps your tank healthy. Once you fish is well just don't add more salt and your normal maintenance weekly 25% water changes will slowly remove it over time.

I hope he gets better soon and good luck with that shark...Yikes!

At Your Service;
Chris Robbins