just started up a 100 gallon pond and all but 4 fish died so we drained it and started again , now its doing better but in the last few days its getting darker in color, i know we need some alge but how much is too much? we have 4 koi and i apple snail and a few - 18 small very small gold fish one lillie pad plant and one cleaner fish cant think of its really name , anything you can do to help us , its not easy being green!!!
You have waaaaayyy too many fish. You can't have koi in such a small pond. A koi pond must be at least 3' deep with massive filtration. You can have 3 or 4 goldfish in a 100 gallon pond.
You also need at least 10 bunches of anacharis and 1/2 of the top of the water surface covered with floating plants.
Check my web site: www.pondlady.com, click on resource center for lots more info.