Green water

[Vegaspond]

Hello everyone this is my first post
My pond is a little over 2 years old now and I can not keep the water clear this year.

I live in a very hot climate 100+ all summer, the pond is in direct sun until my trees get bigger.

1200 gallons with 12 ft of water fall length, Pond master 4800 gph pump with a Pond master pressurized bio filter with a 20 or 22 watt UV light. the water has always been crystal clear until this summer

HELP Please
 

[miguynmkoi]

Welcome Vegaspond!! 

I bet it's hot there!  I'm guessing that if your pond needs shade during the hot weather.  Is the bio-filter box in the sun too?  Could the beneficial bacteria be fried.  You may also need water plants.

There are lots of great people here who will know better if this isn't the case.  Good luck!

[Jonna]

Could the bulb on your UV be dead?  It seems if it kept the pond clear for the previous 2 years, something must have changed.

[Vegaspond]

The bio box is underground and covered with shade. I just replaced the UV bulb in May.
I did slow the flow of the water that is going into the bio filter tonight, I read somewhere that it may be flowing to fast for the UV to work. I split the flow in half part of the water is filtered and the other is flowing trough the bypass valve

[kntry]

How many koi do you have in the pond and how big are they?  If your pond stayed clear for a couple of years and nothing else has changed, your fish load is probably too heavy.  The fish have grown and they're overloading the filter system. 

You also need to test the water for pH, alkalinity and hardness.