Pond Boss Forums MANAGING AN EXISTING POND Fertilization brown water

i have fertilized my pond 3 times in the last 4 months and each time i get a green scum on the top. it goes away pretty quick especially after a rain.
from time to time my water gets brown. i use bag fertilizer. i think the #'s are 5-20-20. my friend says that when he used bag fertilizer it was the same way for him. now he is using liquid and has a greener color to his water.

is there anything to this?

I wouldn't think liquid and granular fertilizer would be much different for a given analysis. It may take a day or 2 for granular to dissolve, but that's not a real drawback.

Green plankton can turn brownish when it dies off. Have you had a lot of cloudy weather or shade from trees? Leaves from nearby trees can also stain the water brown.

Green phytoplankton can also give way to brown zooplankton.

Green phytoplankton can also give way to brown, yellow green, blueish-green, golden brown, and redish phytoplankton. In a lot of instances liquid fertilizer is better than granular fertilizer. I'm not sure right now what makes one work better thatn the other. It has to do with the chemistry of the water and the relationships of the main nutrients, nigrogen, phosphorus and potash. I think in most cases it has to do with the final availability of soluable phosphorus.

What is your alkalinity ? Have you had you water and soil tested?

i check it from time to time with the strips from the pool supply place. ph looks to be around 7 and and the alkalinity is about 50 ppm.

should this stay the same during the winter.