Thank you for your information viz. non-soluble fertilizer, and Potassium. If I ever have to fertilize, it is likely that I will use the non-water soluble fertilizer, following the on-land successes.
As for Potassium, I have NOT done a water test, and should look into it. I have been lazy on this regard, as I have assumed that the water would follow the soil. When I took on this farm, I sent soil samples to two separate labs, and they indicated that I needed No P/K, and in fact recommended against adding any. They also advised against heavy N, except where I have a high N depleting "crop", i.e. grass.
