Question
QUESTION: I have a small 200 gallon pond.  I have about 5 goldfish and a catfish. It has a charcoal filter which I clean bi-weekly.  I have been adding a clear water additive that is safe for the fish.. But I can not seem to get the water clear.. It is not cloudy but it is very yellow/orange in color so I can not see through to the bottom of the pond unless the sunlight is directly above it.  I keep a sceen over it in a effort to keep the leaves from falling into the pond.  I use a fishnet to remove as much of the leaves as I can on a daily basis.. I know some still fall into the pond.. could that be the reason it is yellow?  And if so will that hurt the fish?  
What can I do to get it clear again?

ANSWER: Hello Karen!
The color is probably caused by the leaves. You might want to replace the charcoal in the filter and see if that helps.

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

QUESTION: Thank you .. I have three follow up questions.
1.  Is there a better filter to use other then the charcoal filter?
2. I changed the charcoal two weeks ago and it helped but it is still yellow, How often should I clean the filter and replace the Charcoal?  
3. Will the yellow water harm the fish?
Thank you so much!

Answer
Hello again, Karen.
Let's start with the last question first.
The yellow water is caused by tannin in the leaves. It does not generally harm the fish by itself. Depending of the kind of tree it is, the leaves might change the water chemistry. Keep an eye on the pH.
Charcoal is the best media to use for this particular problem. The issues you encounter with charcoal are
a) it is expensive as filter materials go
b) the way it works is that is has millions of little holes that trap the pollutants, but when those holes are full it becomes ineffective. Consequently it depends on how much it has to pull out of the pond to determine how long it lasts. You might want to add some dense filter mats to assist the filter in pulling stuff out of the pond.