I have plenty of Mg in my tap water, so have never noticed enough deficiency
to add it directly.
Some gets in indirectly because I mix 80% table salt (the silica-free kind)
with 20% Epsom salt for hatching my bbs which I rinse and feed to most of my
fish. Maybe that's another reason I never see any Mg shortage. Lots of
macronutrients come into a planted tank from the fish food.
Wright
-- Wright Huntley, Fremont CA, USA, 510 494-8679 huntley1 at home.com"Congress has not unlimited powers to provide for the general welfare but only those specifically enumerated." --Thomas Jefferson
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