Is there freshwater tests for iron, magnesium, and calcium?
My plants are showing signs of iron deficiency and possibly calcium.
I have searched online and can't find freshwater calcium or magnesium tests.
There's a saltwater kit by Red Sea that has all 3 tests. I wrote to them to see if can be used on freshwater.
Anyone have ideas? I understand KH and GH can help make sure calcium and magnesium levels are good enough.
Multiple planted tanks 1.75g to 55g.