Gallon per foot

[nyvp]

Anyone ever figure out what the Gallon per foot for ......

2"

1 1/2"

1"

3/4"

1/2"

or how many feet needed to make a gallon would be fine as well.
Trying to figure out Total Volume of system.

Thanks

[fsn77]

1 cubic foot (1' x 1' x 1') = 7.48 gallons

1 cubic inch (1" x 1" x 1") = 0.0043 gallons

You're missing a dimension -- you say per foot and 2", etc. but there needs to be a third measurement to calculate volume.

If you're talking about per square foot,

12" x 12" x 2" = 1.25 gallons

12" x 12" x 1.75" = 1.09 gallons

12" x 12" x 1.5" = 0.935 gallons.

[Andrew]

This may come in handy:

http://www.reefcentral.com/calc/vol.php

[nyvp]

sorry I didnt mention I was thinking about tubing. It was clear in my head , just didnt come across in my original question.

[crazyfingersmike]

volume = pi*r^2*h ("pi R squared times height)

for what you're trying to calculate:

pi = 3.14159265
r = inside diameter of the pipe or tube
h = length of the pipe or tube

For example, a one foot section of 1" ID PVC is:

3.14159265 * 1 * 1 * 12 = 37.6991118 cubic inches

...which then needs to be converted to gallons.

0.163199617 gallons

To be honest, I don't know the formula for that conversion, I asked google

[Travis L. Stevens]

Cool information and all, but the original question asks how to determine the total volume of water. You can do this by (length x width x heigth)/231 = ~gallons.

[nyvp]

only problem with LxWxH is that a tube is round not square doesnt that ruin that calculation?

[futrtrubl]

Putting those 2 posts together you get vol = ((pi*r^2)*h)/231 where r and h are in inches and vol is in gallons.

Edward.

[Jamesurq]

Are those internal pipe diameters? Probably not. the schedule of the PVC will determine actual internal diameter.

Thing is - if you have ANY liverock in your system, it's a crapshoot as to what the actual volume is, so I wouldn't worry too much about what's in a few feet of pipe.

[fsn77]

Originally posted by crazyfingersmike
volume = pi*r^2*h ("pi R squared times height)

for what you're trying to calculate:

pi = 3.14159265
r = inside diameter of the pipe or tube
h = length of the pipe or tube

For example, a one foot section of 1" ID PVC is:

3.14159265 * 1 * 1 * 12 = 37.6991118 cubic inches

...which then needs to be converted to gallons.

0.163199617 gallons

To be honest, I don't know the formula for that conversion, I asked google

Actually, "r" is the radius, not the diameter, making r^2 for 1" pipe = 0.5 * 0.5 = 0.25.

Regardless, as mentioned above, unless you took the time to figure out how much volume the LR and sand displaced in your system, any calculation of system volume is going to be off by quite a bit.

Just as an example, I keep track of how many gallons of RO/DI water I make to help me keep track of cost / gallon, as I make water for a friend, also. Our set-up is a 90g with a 15g sump and a 20g refugium (the sump and refugium aren't filled to capacity, about 10g and 17g respectively). If everything was at the full mark, that would be 117g or so. To actually get our system going, when I only had about 90% of our LR, I only had to make about 85g of water to fill it up. Now that we have all of our rock, if I had to guess, I'd say our system probably holds only about 80g of actual water.

[crazyfingersmike]

Originally posted by Jamesurq
Are those internal pipe diameters? Probably not. the schedule of the PVC will determine actual internal diameter.

Right, which is why I said 1" ID PVC (ID == inside diameter)

Originally posted by fsn77
Actually, "r" is the radius, not the diameter, making r^2 for 1" pipe = 0.5 * 0.5 = 0.25.

Doh! My bad. You are correct sir.

So 1 foot of 1" ID PVC is 0.0407999044 gallons. So even with 10 feet of pipe, you only have ~0.4 gallons of water. It's such an insignificant amount to worry about. Even with 2" ID PVC you'd only have 0.163199617 gallons per foot.

Originally posted by Travis L. Stevens
Cool information and all, but the original question asks how to determine the total volume of water. You can do this by (length x width x heigth)/231 = ~gallons.

That is incorrect. He asked about the volume of "tubing" (I assume he means pipe). Tubing is cylindrical, not rectangular, therefor you have to use the calculation of volume for cylinders, not rectangles.

And yes, those that mentioned that it's impossible to calculate the volume that LR takes up, I agree. It's much much more than the amount of water that will be in your plumbing.

Bottom line is, you should assume your total system volume is:

volume of tank + volume of sump

Forget all the other fanciness.

[sirrus6]

FWIW, an alternative approach to calculating your system's water volume can be found in

http://reefkeeping.com/issues/2006-04/pr/index.php

See Experiment # 3.

All you have to do is have the means to measure calcium ion concentration (i.e., Salifert kit) and a source of calcium (I use calcium chloride).

Hope that this helps

Ken