If your pH is stable and (once cycled) you are diligent with water changes, you can do without it for now. It is especially useful in diagnosing pH 'problems' and absolutely necessary before monkeying with CO2.
Ultimately, you'll want one, but you can get away with it for now.
KH refers to 'carbonate hardness', it is more accurately, alkalinity, the sum of all the strong bases in solution, less the amount of H+. Since tank water is more or less neutral H+ and OH- concentrations cancel out and carbonate and bicarbonate are left as the dominant sources of alkalinity.
I think that it's laid out in detail in the "water chemistry" article if you want a little more in depth.
RTR, I think that Sponge Bob mean Ammonium chloride used as a buffer in the tap water, but I'm not positive
Ultimately, you'll want one, but you can get away with it for now.
KH refers to 'carbonate hardness', it is more accurately, alkalinity, the sum of all the strong bases in solution, less the amount of H+. Since tank water is more or less neutral H+ and OH- concentrations cancel out and carbonate and bicarbonate are left as the dominant sources of alkalinity.
I think that it's laid out in detail in the "water chemistry" article if you want a little more in depth.
RTR, I think that Sponge Bob mean Ammonium chloride used as a buffer in the tap water, but I'm not positive
