Pool Sand Filter Help!! Green Water!! High Electricity!!

Hello to all ponding experts. I would appreciate a few of you taking
the time to post a reply to the following question. I am in dire need
of help.

My setup consists of a 2200 gallon concrete lined pond with a hayward
1.5 hp pool pump which pumps at about 90 gpm and it has a filter
basket, and a hayward s180t sand filter, which has a flow rate of
about 35 gpm. My pond has a water fall and a bottom drain. When i
first filled the pond everything was good for about 3 months, then it
started getting green. The initial media for the filter was silica
sand. But after a few months i had to backwash everyother day. So then
i switched to lava rocks. They worked ok for about a month and then
started clogging up just as fast as the sand. I have some plants in
the pond, but the sand filter is about the only filter i have on the
system. I wouldnt mind flushing the filter if at least the water
stayed clear. I live in Tucson AZ, where it gets pretty hot and sunny.
My backyard is new so i dont have a lot of shade. i planted trees, but
they just dont seem to grow fats enough. I had a total of 4 koi to
start with, but 2 have died off, and im pretty sure it has something
to do with the green water. I am looking to find a home for these 2
fish if anyone in the tucson area is interested. ohh yes, also my
electricity bills are way too high because of running the pool pump
24/7.
So with all of my pond problems listed, i would greatly
appreciate some help. I have been looking to buy a moderate priced
filter and pump system, or maybe build one myself. If anyone has any
ideas on how to modify my current setup, or media types for the filter
i could use all the help i can get. Or if anyone has suggestions as
for what to but to fix my problem. I also forgot to mention that i did
try the liquid pond cleaner bacteria and had no luck.

I really will appreciate any advice. Thanks for the help in advance.

Matt Clark