Dying Angel fish and Bala Sharks

Question
I have 5 x Bala sharks and (had) 3 Angel who lived very happily in a 50 golon tank for the last 18 months.

A week ago I got a second hand 66 gollon tank. The tank was running for more than a year with 25 Malafish in without being cleaned (dirtiest thing I have ever seen).
I gave away the Malafish as I wanted the tank for my Bala Sharks (the biggest one being about 9 inches) and Angel fish. I drained the water, rinsed it out, rinsed off the stones and ornaments in the tank, cleaned the filters, refilled it and treated the water for Chlorine.  

After running the tank empty for 48 Hours I added the Angel fish and Bala Sharks. Since i put the fish in they are not eating. This morning (after 6 days in the tank) I found one of my Angel fish dead. The Bala Sharks are also getting sore spots and it looks like there scales are falling off.

What can be the reason for this and how can I rectify it?

Answer
Hi Stephan!

Well it's most likely the chlorine. Fish do not survive we'll in chlorine. I suggest you to remove the fish immediately and drain out the chlorine water then refill the tank with dechlorinated tap water. Also, make sure the pH levels and the temperature for the Bala Sharks and Angel Fish are correct.

Hope this helps!

~ Sam