cloudy fresh water aquarium

Question
QUESTION: I have an established 46 gallon tank with a 7" Plako, a 12" clown knife, and a 6" oscar.  The water will not clear since I did a 25% water change 3 mos ago.  I have used different clarifiers and did 5 and 10% changes and left it alone for a few weeks and it will not clear.  Any suggestions?

ANSWER: Hi Steve,
The tank is probably still having trouble keeping up with the bio load of the fish.  Since you have huge fish, of which all hive high bioloads, the tank must need a great deal of beneficial bacteria in order to keep things under control.  Once it is, it will clear.  I would also suggest a bigger tank because these fish sound really large.  Smaller tanks will stunt its growth and will cause health problems.  
-Matt-

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

QUESTION: Thank you for your help.  What can I do to help the tank create beneficial bacteria till it clears?  Should I not do water changes?  Should I change the water more often?  Is there something I should add like Cycle on a daily or weekly basis?

Thanks for your help.

Steve

Answer
Right now, all you can do is just give it time until it cycles.  Excess food and fish waste will be converted into ammonia, which bacteria will eat and change it to nitrite.  Then another set of bacteria will eat that and convert it to nitrate.  As long as the fish are being fed, the tank is in the process of cycling.  

You must do water changes because high ammonia or nitrite levels left alone is toxic to your fish.  If you have a liquid test kit, you can measure these toxin levels and adjust your water change schedule according to the readings.  Liquid test kits test all of ammonia, nitrite and nitrate and costs about $30 at pet stores.
-Matt-