For more accuracy
we subtracted the 0.3 gallons for the water
displaced by the rock from the 10.6 gallons
to get 10.3 gallons of water in my aquarium.
There is still the gravel in my aquarium with
an estimated thickness of 1/4inch.
The bottom
of the aquarium measured inside is 11.75 inches
times 17.75 inches = 208.6 square inches.
At
1/4 = 0.25 inches thick or 208.6 x 025 = 52.15
cubic inches of gravel on the bottom of my aquarium.
Next multiply this number by the same conversion
factor, 0.00433, to convert the answer to gallons:
52.15 x 0.00433 which is about 0.23 gallons.
But the layer of gravel is not solid gravel,
it is, say, 50% rock and 50% water.
So take half of 0.23 gallons to get 0.11 gallons.
Of course, this estimate of the gravel might
be a little inaccurate.
I'd say it might be
half as much or twice as much. So it's likely
between 0.05 and 0.20gallons.
I could put all the gravel in the bucket and
measure its volume just like I measured the
volume of the rock.
But for now I'll use the
calculated value of 0.11 and subtract the 0.11
gallons from the 10.3 gallons to get about 10.2
gallons.
Not much of a difference, so I can
probably ignore the inaccuracy in the volume
of the gravel.
There's about a pint of water in the filter
that hangs on the back of my aquarium.
A pint
is 1/8 of a gallon, or about 0.13 gallon. Add
that to the 10.2 gallons to get back to 10.3
gallons. I think this number is pretty close.
The first easy measurement and calculation gave
11.2 gallons of water in the aquarium.
A more
refined measurement and calculation, that took
a lot more time, gave 10.3 gallons. So I'd put
10 drops of Quick Cure instead of 11 drops.
This is one drop less and probably wouldn't
matter anyway.
But it's good exercise to make
these calculations and to find out that the
original number 11.2 was probably close enough.
The more accurate number, 10.3 gallons, is more
accurate than we needed.
