What exactly is aquavitra IONS ? Is it supposed to be a magnesium supplement? To raise your mag levels, simply dose epsom salts. Use this Reef Chemistry calculator
to determine how much to dose.
I don't know what aquavitra 8.4 is supposed to be, but there is nothing that will raise pH to a certain level and keep it there. The more you add, the higher it will push your alk
. Sodium carbonate (baked baking soda) will raise your pH and also raise alk
. 8.2 is fine for your pH.
The green slimy stiff on your rocks sounds like cyano
. Usually caused by poor water quality/high nutrients.