Finicky Koi and Algae filled garden

Question
QUESTION: I'm not sure if I need to post two different questions or not but here I go with them at once. We're having trouble with algae. We've changed the water several times and bought a filter for it. As well as these pads that collect bio degrade that catch algae. Usually two days later, we end up with murky water. How do I solve this?

We recently got some koi as well, they're really finicky, how do you get them to calm down?

ANSWER: Hi,
If you are having trouble with green water I suggest you buy a UV filter which will definitely get rid of the green water,Changing the water will NOT help it will just keep going green and murky, may be change a little evry day but not all of it at the same time.
If you keep changing the water the koi will be finicky as they prefer mature water.
George.

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

QUESTION: Do you know how much a UV filter usually runs for? After we do another full change, we'll start with the changing a little bit of water each day.

We've had them about for 5 days now [the koi], They haven't gone through a complete change yet. They were replacements for the ones a raccoon ate. Any idea how to get them to calm down? Or if there are foods that help?

Answer
Hi,
if your koi are really unsettled it could also apart from the water quality maybe that your pond is to shallow and they get startled when anyone aproaches they can pick up the vibrations of anyone walking nearby through the water. and Uv filters are not expensive but you will need one to suit the volume of water in your pond.
George.