Planted Tank Enthusiast
Join Date: Dec 2003
Location: Valley Stream, NY
Can ferts go bad?
I have been using 2 year old dry potassium nitrate from Greg Watson to dose my 20 gallon aquarium. After weeks with this aquarium I've noticed plant growth that lead me to believe of a nutrient deficiency.
Since I have no fish, the first thing I thought was a deficiency in nitrate. I do EI dosing so I would normally dose 1/4 tsp 3x a week. Before I did a water change yesterday I tested the water and it came to 5 ppm of nitrate (after 4 days of not dosing.) I dosed 1/2 tsp after a water change and tested the next day, nitrates come to about 10 ppm.
I did a little experiment disolving 1/2 tsp of potassium nitrate in half a cup of water and tested that. It only came to about 15 ppm of nitrate. BTW the test kit was bought Sunday and is made by API.