[Boomer]

if i had to take an educated guess using some other calculators, i would say that i am somewhere around 48 gals

That sounds like you have a 55 gal tank. Lets pretend it is a std 55gal

48 1/4 x12 3/4 x21 = 55gal tank in shipping dimensions ( is what they go by) The glass is 1/2 inch thick so, 47 1/4 x 11 3/4 x hight of water inside tank, say 20 inches.

47.25 x 11.75 x 20 = 11103.75 cubic inches divided by 231 cubc inches, the numer of cubic inches in 1 gal of water = 48 gal of water with no displacement.

It is hard to cacluate water displacemnet as LR can have different porosity. Corals, fish, tubes, pipes, heater, powerheads, etc. all displace water. So to be safe figure 25 % or 35 gals. If you have a sump you need to add that to the 35 gals. Lets just go with 35 gals and raise it 20 ppm


7.3 grams; 0.2 oz; approx 1.4 tsp to raise it from 350 to 370. If you do not have a sump I would add 1 1/2 tsp and then cehck the Ca++ a couple of hrs later to see what you get and then go from there. Lets say the Ca++ goes up 22ppm Ca++. You can then plug a gallon value into the caclualor until it comes 22ppm when it with 1.5 tsp . You will now know about what the volume is. It would come up 32.5 gals @ 1.5 tsp to raise the Ca++ 22 ppm