when u have stony corals, when they grow they absorb calcium and carbonates from the water... to make it even more fun they dont absorb them in the same amounts. the more calcium goes missing the higher the alkalinity. Also if the alkalinity gets too high then calcium starts dissapearing... but anyway when u have a big tank theres a bit of a buffer... but in a 10 gal it changes very fast n as u prolly know reefs do best when everything stays constant
since i put those corals in the 75... they been growin crazy fast
but u have nothing to worry bout cuz i dont think u have any stony corals