P - tests in the past have not shown outrageously high amounts, just this summer. I suspect that the lower than normal rainfall last year and the much higher than normal rainfall this year has created a large influx of P from the watershed (lots of fertilized lawns). This pond is also linked to several other ponds in the community, so I believe that it is a cumulative effect.
How can I test the soil? Are those diy garden tests sufficient or should I send it in?