I could use some help understanding the Water Quality Report for my city (since I use tap water for my aquarium). I know that the water parameters that I start with are important to consider when calculating fertilizer doses.
Nutrient deficiency problems have gradually been getting worse over the past few months in my aquarium. Several months ago, however, my plants were doing amazing. I had had a lot of plant growth and increased my fertilizer dosing over time--but I must need to increase the amounts even more. I don't want to go too crazy with the fertilizers. I'm not the type to just dump something new in and see how it goes--I'm more precise and careful.
A concern of mine is preventing osmotic shock for my fish during water changes. The values in my aquarium are usually GH=8-10, KH=2-3, and pH=7.4. The values of my tap water are usually GH=3, KH=1, pH=around 7.0. When doing water changes I raise the GH of the "new water" from the tap by adding Seachem Equilibrium to match the GH of the aquarium water +-0.5 degrees. Likewise, I use Seachem Alkaline Buffer to do the same for KH. The GH and KH are higher in my aquarium vs. tap due to regular use of Equilibrium (for plants) and seashells in my filter (for more stable KH and pH).
If I am reading my city's water quality report correctly, the annual average is 0.006 ppm of calcium and 0.0019 ppm of magnesium with a 7.3 pH average. Does this mean that my plants are really only getting calcium and magnesium from my water changes when I add Equilibrium? Am I reading this report correctly?
Water Quality (2018 annual?) Report https://www.cfpua.org/Archive.aspx?AMID=54
Jan. 22, 2020: water tested in my area has the highest level of PFAS contamination in tap water in the U.S. I don't know if that would have an effect on plants, but it's been a known problem in our water for many years.