Bala Sharks suddenly dying... Help!

Question
I have a 120 gallon tank that is approx 6' in length. It is a community tank, and has various gouramis, a school of neon tetras, a roseline shark,pleco and a mixture of fake & freshwater plants. It is an established tank for about a year. The balas have both been in there for over 8 months. One is slighty older and larger.

Recently the older of the two had developed what looks like blood streaks in fins, but it was very minimal.

I did a 20% water change and vacuumed the tank. Then I added the appropriate maintenance chemicals. This was done about 5 days ago and everything seemed normal.(excepth the slight redness in the one bala shark)

Yesterday the big one was twitching and breathing rapidly. This morning he was upside down and dead on the bottom of the tank. Now I am seeing similar twitching and rapid breathing in the other bala. None of the other fish seem to be affected.

I really want to save the Bala shark, what can I do?

Answer
Dear Kyle,
Wow,I'm so sorry to hear that... :(
Red streaks in the fins is usually an illness known as septicemia. It is particularly a bacterial infection in nature, mostly caused by poor water quality. Everyday large water changes are best for this condition. I have sucessfully treated fish with red streaks by changing 50% of the aquarium water everyday and treating with Melafix and Pimafix used together. An addition of aquarium salt also helps. I understand given the size of your aquarium that 50% everyday water changes would be almost impossible.
Could the Bala shark go into a hospital tank? If you could gently move him into a hospital tank of a smaller size that would be best. The hospital tank must have the same water the poor Bala shark is accostumed to already and it must be filtered. Moving spook prone fish is a tricky process and is even worse in a large aquarium like yours. Because he is already stressed, could you (with the help of a large net) herd him into a 1gal aquarium safe pitcher? I have done this with large frightened severums whom were bigger around than your hand. It is much better for stressed fish to be moved in a container rather than carried in a net.

What I would do is-
1. Test your water (ammonia,nitrite,nitrate)
2. Move Bala shark into hospital aquarium
3. If the above is not possible... Try changing 20% of the 120gallon's water everyday and use Melafix and Pimafix treatment. (Changing much more water is better. If you could manage even 40% every day that would really help)

I'm very sorry to hear about your Bala sharks. They can be quite sensitive creatures. I hope this helps and I wish you only the very best with them!

Karen~