Rubbermaid stock tank sump question?

[Smitty750]

I have a 100 gallon stock tank for a sump and I want to make a wate level marker that shows how many gallons are in it in 10 gallon incriments. This way I can just open my dump valve till it drains to the correct level, making water changes easier and faster. What's the easiest way to do this? Cause I used the tank volume calc with the dimensions of the stock tank 53" x 32" x 25" it gave me a total volume of 184 gallons??? Its only a 100 gallon Rubbermaid so just wondering if I did it wrong or if any others have experience with this?

 

[rdelong]

The calculator assumes a rectangular volume such as a standard aquarium. If you tank is the one I have it is oval and tapered in three steps top to bottom. The rectangle created by the maximum dimensions of that tapered oval tank would hold considerably more volume. I think you will probably have to use the old method of successively adding 10 gallons and marking the levels since the level calculator won't give you accurate output.

 

[SHOmuchFUN]

Yep, what rdelong said...

Or you can empty the stock tank's contents into a known volume container and mark the locations. Works the same way.

What I do, is just empty the stock tank into a brute container to a certain level and make sure I use the same size brute container and fill with the same amount of saltwater. No real need to mark the stock tank using this method.

 

[Smitty750]

Cool thanks guys Ill give it a try

 

[acurro]

I just did this with my rubbermaid garbage can I use for making seawater. You can calculate the rectangular portion using the tank formula, then use your imagination to cut the two oval portions off the left and right of the sump and calculate them together as an ovaloid.

See this website. Calculate the area of the total ellipse (of the left and right segments), then multiply it times the height of the water column. Then divide by 231 (?) for cubic inches in a gallon.


http://www.math.hmc.edu/funfacts/ffiles/10006.3.shtml

It isn't really too complex.