Erm, what does PH, kh, and gh all mean in layman's terms?
Im 19 but I failed chemistry, so hear me out here. Uh, i found these three tests in my liquid test kits that i werent using because people said they didnt matter. Out of curiosity, i tested those anyway. What i tested was ph, gh, and kh. My ph is 7.5, my gh is 4 if i tested correctly, and my kh is three. What on earth does all that mean? Oh and how to i know my tank light is bright enough for the aquarium plants that require lots of light? I have a hooded light with a looong 18 cyllender shaped 15 watt bulb that says it gives off 18000k of light.