Sick Cichlid tank

Question
This will be a long question/issue since we have been dealing with this tank since July. We have a 46 gallon bow front tank. Ph, Amonia, Nitrite and Nitrate are OK. We have battled cloudy water forever. We set up the tank, later realized too many rocks and one may had a fungus so....6 weeks ago we took out all the real rock, gravel and decor..we now have black gravel and a large plastic rock with hidey holes. That's it. For Filtration we have 2 Aqua Clear 70 ( so they are pumping 300 gallons per hour) and 1 Marineland canister filer pumping 250 gph...everyone kept saying we needed more filtration. We have 7 Cichlids, 2 cat fish things and 2 pleckos. The  2 cat and 2 plecko's stay hidden in the rock. We can't seem to get rid of the cloudy water. We were told to wait 1 month before cleaning the filters to let the bacteria establish..at the 1 month mark the water got even more cloudy ( we are on county river water) so I rinsed the filters and the water has filtered and is still cloudy. Could a sick fish make the water bad? We had ick several weeks ago and treated it, but our yellow peacock developed a cloudy eye and a funky spots ( not ick, but more like a fungus since the spots were larger). We bought a 5 gallon tank put him in it and treated with Tetracylen for 2 rounds...he didn't get worse, but didn't die either.  4 weeks ago when we re-set up the tank we added him back. His head now his white like his skin is missing, I noticed that part of his right gill is gone (small chunk) and now I have a Strawberry Peacock with some scales missing on his back, but no skin missing. I have been watching to see if any others get funky spots or sick looking....but so far it is just the cloudy water and yellow peacock that are the biggest issues.  PLEASE HELP!! but husband is so over this tank and ready to flush the fish. I have way too much $$$$$$ invested ( needless to say we could have set up a salt water tank by now) with all the extra filters, chemicals, decorations, etc that we have changed. THANK YOU for any help or advice you have, it is really appreciated.

Answer
Hi Jessica,
The only thing that can do this is poor water quality.  Your ammonia must be zero, your nitrites zero, and your nitrates must be low.  When scales are missing it is caused by ammonia burn.  Also, I do not know what other fish you have in your tank, but African Cichlids must have hiding places.  Overturned clay pots, and rocks are a must when keeping these cichlids, and the decorations in your tank must be changed monthly or fights will break out, and they will bite each other.  By this I mean that you switch the rocks around so they get all mixed up, and make new territories.  When these fish get too comfortable with there territory, fights will happen.  They are aggressive, and territorial fish.  They need hiding places to feel comfortable.  If they do not have rocks, caves to hide in, they will get stressed, and stressed fish get sick. Check your water for ammonia, and nitrites, and nitrates.  Also check your PH.  African Cichlids must have a high PH.  This means 7.6 to 8.0.
When cleaning your filter, never clean the sponge under tap water.  The sponge is full of good bacteria that fish need to survive.  Clean your sponge with water that you have removed from the tank.  The sponge is good for a very long time, until it is old, ragged, and falling apart.  If you have rinsed your sponge under tap water, you have killed all the good bacteria in your sponge.  This could be another reason why your tank is cloudy.
You should not have had all of these problems.  A tank must cycle, and usually this will take 6 weeks to get it going properly.  Fish must then be added slowly.  I am wondering if you have done this, because this is one mistake that people often do.  When adding fish to a tank, you must add two, wait one week, do a 25% water change, and if your water chemistry is right, add two more, wait one week, do a 25% water change, check your water chemistry, and so on.  Weekly water changes are very important.  When adding a new fish to your tank, always switch the rocks around so the Africans will be busy making a new territory, and forget the new fish that was added.  I also boil my rocks, let them cool before putting them into my tank.  I also check them by putting a few drops of PH down on the rock.  If the rock shows bubbles, I don't use it, if it doesn't it is safe to use. This is the only thing that PH down is good for!  Never use this in your tank, and never use PH up in your tank.  They cause the PH to fluctuate, and this is bad for any fish.
Cloudy water happens when you add too many fish at once.  This is called "Bacteria Bloom"  The fish waste, and therefore ammonia level spikes, nitrites go up, and you may lose all of your fish.  Adding chemicals is the worse thing you can do.  Water changes are the only way to get rid of this.  
For now, do a 30% water change, and do not clean your sponge.  Do small water changes of 10% everyday until your water chemistry is perfect.  Siphon your water from the bottom to remove all the waste, and uneaten food.  Change your carbon every month.  Your carbon may be rinsed under tap water.   If your water is not alkaline, buy crushed coral, rinse it well, and make a bag out of white nylon stockings.  Put a little handful of coral into the bag, and put it into your filter.  Let your water run over the bag.  Check your water in 24 hours to see if the PH went up, and if it is right.  If your PH is still too low, add another handful, and wait one day, and check again.  Bringing up the PH must be done slowly, as bringing it up too quickly would cause death.  You can also add sea shells.
I think your problem stems from adding too many fish at once, or maybe your tank had not cycled properly from the beginning.  Please do not give up.  It is common to make mistakes when first starting a tank.  Pet stores will try to sell you all kinds of chemicals.  Unfortunately, these never work, and make your water worse.  Please do not flush your fish, they do feel, and the kindest way to put them out of their misery is by using clove oil.  You will get all the information you need on the web.  Google it buy putting in "how to euthanize a fish."  I must tell you that I think it is too late for your yellow peacock, but sometimes they do get better if your water chemistry is right, and with water changes.
A fish cannot make your water cloudy unless he is dead, and left in the tank.  Two plecos is too much for a 48 gallon tank.  One would be sufficient.  You must feed plecos like you do other fish with sinking algae waffers, and sinking shrimp pellets.  If you do not feed them, they will starve.  Since they are hiding, this is not a good sign.  Maybe your pet store will take one back.  I hope so, as the common pleco will get very big.  This takes time, but they do outgrow the tank.  With African Cichlids, you really don't need a pleco since they too eat algae.  Another mistake is to think that plecos will eat rotting food at the bottom of the tank.  They don't, they are a fish, and need to be fed food like any other fish.  Never count on a pleco, or other bottom fish to keep your tank clean.  You must do your water changes every week once your water chemistry is perfect.  Fish waste, and uneaten food will make your tank cloudy.  With patience, and water changes you will get rid of this, but it may take time.
I hope this will help.
Lynda