If Tracy wants pond results to be exactly like those witnessed in the sample jar, then I contend that he will need to use the calculated amount of product. Suggesting that he could benefit from less product to lock up phosphorous may be valid, but is not based on his experimental testing.
Personally we have experienced the same problem of high pH, low visibility, and super-dense plankton blooms, due to the high alkalinity/ low hardness phenomenon.
Last season I used 600-700lbs of alum per acre -ft in one pond (alkalinity 200ppm) to bring down pH from 10 to 7-8 range. Visibility improved only slightly, and due to high alkalinity, ZERO hydrated lime was needed.
Again, in another pond, we used 300-400lbs alum per acre-ft to bring down pH, also with ZERO hydrated lime.
The decision to use or not to use hydrated lime should be made by testing pH during the alum application process. Using hydrated lime blindly without testing pH during application may result in no significant pH drop.
I want to be clear that I am not recommending that Tracy apply 2867lbs alum per acre-ft. I am suggesting that he would need this amount to match his experimental testing results. This data may suggest that alum application is not feasible.
If the decision is made to apply 200-300lbs alum per acre ft, I would think that the specific goals of this alum application would need to be laid out in specific terms.
How much would visibility be expected to improve? How low will this drop the pH? Will hydrated lime need to be used? If so, how much. Maybe the average pond requires 200-400lbs per acre-ft, but what if Tracy's pond is an exception, due to exceptional water quality parameters?
Last edited by overtonfisheries; 02/10/18 04:24 PM.
