pink water lilies in front of islandf

I have had my pond for over 6 years and we have experimented with various methods.  I have a rubber liner, about 20'x20' and two waterfalls with a pump that takes the bottom pool back up to the top waterfall.  It recycles totally about ever 2-3  hours - has about 16,000-17,000 gallons of water. 

This year for the first time, I had a problem with green water, and though I realize it is good for Koi's, I only have one and the rest gold fish (25) with one carp,  The center depth is over 4' and I sink my water lilies down to the center in late fall and bring them up after the pond has thawed thoroughly and we can reinsert the pump, etc.  

This year I separated all the rhizomes and went from 8 to 33 potted water lilies.  My flowers are much smaller, but that seems natural to me with the separation.  I also used water lily fertilizer in all of them and perhaps this threw off the ph of the pond, causing the green water.

We have finally gotten it balanced, but every expert I talk with and book I read keeps emphasizing that I need bog plants.  I have arranged for this with big tubs that are submersed in a quiet area of the pond and will plant them in the Spring.  However, it seems wize to fill them with the soil this fall to give it time to settle and reach a good balance.

I have great difficulty getting pure clay kitty litter - it all has additives and I don't want to put them in my pond.  I finally went to the local clay shop (worldwide known Archie Bray) and purchased some non pugged bags of Missouri Flint Clay, Hawthorn Bond Clay, STKO, Bauxite, Plastic, Fireclay, Disapore Clay, Burley Clay, Rotary Kiln Fines, HR.  If I mix this 1/2 powered clay to 1/2 soil (which is pretty clay-like and coarse), should this work for my bog plants?  I don't want to poison my fish or plants!

Any advise greatly appreciated and I do realize Bentonite can be used as a liner, but was concerned it would not contain the water well enough over the entire pond.  My bog containers are solid, so that is not an issues.

Thank you for any help.  I will be performing your quart jar test today to see if I can further determine the right mix.

Thank you.  Dorothea Sams

7347 Sweeney Creek Road

Helena, Mt  59601

800/227-6090

(we have a home business so are usually here)

p.s.  We live at 4600' altitude and everyone is amazed we are able to grow such great waterlilies at this height!  But, we do!