Question
I HAVE A KIDNEY POND ABOUT 3FT WIDE X 1FT DEEP WITH 4 GOLD FISH IN IT ONE PUMP CIRCULATING WATER AND ONE POT WITH WATER LILY THE PROBLEM IS WHEN I CLEAN OUT THE POND IT DOESN'T TAKE LONG BEFORE IT GETS DIRTY WITH GREEN ALGAE AGAIN.

HOW OFTEN DO YOU NEED TO CLEAN POND WILL IT KILL THE FISH
IF YOU LEAVE IT DIRTY FOR A WHILE

Answer
In order to safely have fish, you need the pump to circulate through a filter that has bot mechanical and biological sections.  This way you can clean out the mechanical media without disrupting the bio section.  Also, make sure not to overstock your pond with too many fish.  The algae is growing because of both sunlight and nutrients in the water.  If you eliminate a portion of either of those, you will see less algae.  Do this by adding plants, which serve to both block some sunlight and use nutrients that algae uses too.  I don't recommend cleaning the water out very often because the same bacteria that collect in the bio-filter area are also in the water.  I do recommend about a 25% water change every month to get rid of some nitrates.  All of these potential problems become a lot more likely the more fish you add.  Make sure, if this is a new pond, that it is able to go through the nitrogen cycle.  If any of the terms I used are foreign to you, google them and prepare for a good read :)