Thank you, patryuji! (for the kudos, and also I would not have tested kH and
GH otherwise!) It was interesting that my (and some other people's)
GH fell after the water change. Not by much, but it did fall. I wonder why? (is that a newbie question?
I don't know a lot about water chemistry.) I know that the pH may fall a bit due to the acidic waste in the aquarium, but I wonder why
GH rises through the week, while my
KH stayed constant in each tank, even though the values were different in each tank. Something in the gravel??
TankGirl, why do you do a water change so often, and with large water volumes, in your planted tanks? I thought fertilizers replaced what the plants use. (is that another newbie question?? lol !)