Cloudy tank, suspected shark disease??

Question
 Hello Karen. My name is Nick and I would greatly appreciate it if you could help me with a few problems I seem to be having with my freshwater tank. My wife and I got our tank on Sept. 21st as a wedding present from one of our friends. My wife and I have long been intrested in aquariums, but this is our first time owning one. We stocked with two blue grommies, two spotted catfish, three fan-tailed guppies,two fancy sword tails, two red fin sharks,(we recently added two more because we heard that is best to keep down aggression) and some kind of giant gray grommie.:)( we have a thirty gallon tank) Everything went fine untill about two weeks ago when our water started to get cloudy. We changed filters, added crystal clear, changed filters again and again, but now we seem to be out of options and our water is even worse than when we began. Not to mention our two new sharks have been rubbing on each other a bunch, and now they seem to have white, raw looking spots on both sides of the dorsal fin on their backs. They don't look so great either. Everything else seems to be fine and all the other fish are healthy,and it really looks like the skin is missing, not crystals like ick. Is my cloudy water and sick sharks connected? I really hope that you can shed some light on my situation, and would greatly appreciate any advice you can offer.
Thank you very much, and hopefully I will hear from you soon.
                                       Nick Thorpe

Answer
Hi Nick,
Sorry to hear about your aquarium trouble.

What probably has happened is your tank has gone through a bacterial bloom from some kind of imbalance in your tank. Bacterial blooms are caused by nutrient imbalances either from overfeeding, or disturbing the beneficial bacteria that thrive in your tank and help control ammonia and nitrites produced by the fish. The bacterial can be wiped out if you over-clean your tank or if you changed out the filters too frequently. But again, overfeeding or not cleaning your tank often enough can also lead to bacterial blooms clouding your water.

The two best things you can do is to test your water and take note of the ammonia, nitrite, and nitrate levels. In healthy aquariums, these levels will be as follows- Ammonia-0 Nitrite-0 Nitrate- 20 or less.

If any of these levels are out of the range they should be. An immediate water change should be done. Its OK for the nitrates to be slightly above average but you should aim to try to keep them as low as possible. If you have even trace amounts of ammonia or nitrites then you could have a serious water quality problem because both ammonia and nitrite are very toxic to fish.

As for now, and to clear up the cloudiness. The best thing you can do is to start changing 50 of the tank water everyday and make sure to leave the filters alone. If you could test your water that would help us further on what the best steps are to take. But for now, just do the 50 water changes and make sure to gravel vacuum everyday. These water changes will not harm the fish and it is the best solution to any water quality problem. In my experience, chemicals which are meant to clear the water have never worked for me.

Be patient, even though it may not seem like its doing anything, with time it can help and eventually the conditions in your tank will stabilize and it will clear.

Concerning your Sharks... The first thing I'd suspect is the sharks may be fighting. Almost all sharks  (with the exception of Bala sharks) are very territorial and will fight each-other quite savagely sometimes. They may only fight when you are not around or just at night. The wounds on them are tell-tale signs of fighting. Its best to only have 1 shark per tank unless the aquarium is very large of 55-gallons or more. The only thing you could try is to provide as many hiding places as you can for the sharks to stake out their territories. But most likely this isn't going to work. :(

I really hope this helps and best of luck!
Happy holidays!
Karen~