Many questions about a tropical fish tank

Question
QUESTION: Lynda,

Well I have a bunch of questions about a tank that i am
taking care of. Now this isn't my tank and i believe that
this tank needs some help. So its a 55 gallon tank it has
about 15 fish in it witch includes 3 bala sharks, 2
placostumos catfish, A lemon yellow mbuna Cichlid,  about 6-
8 black convict cichlids, A pink? chilid and a shark that
looks like a catfish. The tank is at 77.8 degrees right now,
it has 2 heaters and 2 water filters witch 1 is off right
now. I used one of the water test strips and all the levels
are way to high.

Ok so my questions are the tank smells horrible and im not
sure what to do to make the smell go away. Also the convict
cichlid black stripes arnt as dark as they were, some of
them almost look like they are gone. Also there are baby
black convict cichlids and pink ones also and i have no idea
how to take care of them. the convict ones are in a smaller
tank but the others are in the big tank. Please help me with
cleaning the tank up and making them healthy. Thank you

Meighen

ANSWER: Hi Meighen,
Your first problem is that your tank is overcrowded.  Bala sharks grow to 12 inches, sometimes bigger, and they need big tanks, at least 150 gallons or more.  Two pleco catfish is too much for your tank.  They also grow very big, 2 feet, and more.   Catfish sharks also grow very big.
Your water quality is another problem.  Your ammonia level should be zero, your nitrite level should be zero, and nitrates should be low.  If any of these levels are high, you have one big problem, and may lose all your fish.

Take your sharks, catfish, and Pleco back to the pet store.  These fish will grow too big for your tank, and it will also give you a chance on getting your water back to normal

Do a 50% water change.  Both filters should be working.  
Do 20% water changes every day until you get the water chemistry right.  
The horrible smell comes from a neglected tank.  Water changes should be made every week without fail of at least 25%.
Fish waste, and food fall to the bottom, and if not removed, poisons your water, so always syphon you water from the bottom, and always use a good water conditioner when doing water changes.
When a tank reaches this level, it is very hard to come back to the right chemistry.  It's a long road ahead, and your only option is water changes every single day.  Removing fish will help.  
The fact that your fish have fading colours, is not a good sign.  They are stressed, and stress causing disease.  Dirty water also causes disease.  Hopefully they will pull through with the water changes. I cannot guarantee this.

Rinse your sponge from your filter in water that you will remove from your tank.  Never rinse your sponge under tap water.  Your sponge is full of good bacteria, and you don't want to kill it.  If you haven't changed your carbon, please do so.

Convicts are excellent parents, and should be left with their babies.  Since you have removed the parents, and the fry are on their own, you will have to feed them baby brine shrimp that you find in your frozen fish food section at your pet store.  This must be "Baby" brine shrimp.  Feed them 4 times a day to begin with, and in 2 weeks bring them down to 2 or 3 feedings.  In about 2 weeks, you can start feeding them a good quality flake food that you crush to the size of pepper, alternating with baby brine shrimp, then later, feed them bloodworms, flakes, and vary their food so they will be healthy.  Do water changes in the fry tank of 10% everyday.  This too is very important.
I hope you save your little friends.
Lynda

---------- FOLLOW-UP ----------

QUESTION: Hi Lynda,

OK well I lost 2 fish and made the small tank really dirty
and stinky, So i had to start over completely. The mom and
babies are still alive but the other female and male that
were in that tank didn't make it. So the mom seems to be a
little slow i haven't put them back in the tank yet I'm
going to let it sit over night and "settle" persay.Now I'm
wondering if theres anything i can do to nurse her back to
health. I haven't had time to clean the big tank yet but
will be doing that tomorrow.

Answer
Hello,
The only thing you can do is make sure you have no ammonia, nitrites, and that nitrates are low.  If you do not follow the rules of fish keeping, they will all die.  You cannot cure fish in dirty water,or water that hasn't cycled.  The medication would make things worse.
A tank should run for 2 or 3 weeks without any fish in it.  After 2 or 3 weeks you check your water to see if the chemistry is right.  If your ammonia level is zero, and your nitrites zero, and your nitrates safe, then you add one fish or two if it is your 50 gallon, and wait one more week.  Test your water again.  If it is still safe, change 25% of your water, and add 2 other fish, and so on.  You must change 25% of your water every week when you have fish in your tank, and this is a "Must Do"  If you add too many fish at once, your water chemistry will change, causing death to all fish.
You can buy these small test kits at your pet store, and they should be number one in your fish cabinet.  
For now make sure your water chemistry is right, this is the most important thing you can do.  Fish living in dirty water will get sick, and your water must have the right chemistry to cure them.  Ammonia is the number one killer of fish, so you see how important it is to have the right chemistry.
I hope you understand, if you have any other questions, please write back.
Lynda