Rectangular Tub
This table shows how much extra water is used when the trough level goes up just a few inches. You may wish to mark the inside wall of your trough to identify different water levels. If you wish, we will be glad to do similar calculations for whatever size trough you are using.
| Dimensions in Feet (length x width x water height) |
Total Cubic Feet (L x W x Ht) |
Gallons Per Cubic Ft |
Total Gallons (L x W x Ht x 7.48) |
| 8 x 4 x 1.25 | 40 | 7.48 | 300 |
| 8 x 4 x 1.0 | 32 | 7.48 | 240 |
| 8 x 4 x .75 | 24 | 7.48 | 180 |
| 8 x 4 x .5 | 16 | 7.48 | 120 |
Round Tub
The following calculations were done on two sizes of round troughs. You may wish to mark the inside wall of your trough to identify different water levels. If you wish, we will be glad to do similar calculations for whatever size trough you are using. With regard to the issue of using as little water as possible for CS-530 (Patent Pending), please note that for a 6 foot tub, each 6 inches of water equals about 100 gallons. The formula used below for cubic feet is Pi x R2 x Ht.
| Diameter in Feet |
Radius in Feet (R) |
Radius Squared (RxR) |
Pi | Water Height in Feet (Ht) |
Total Cubic Feet |
Cubic Feet per Gallon |
Total Gallons (Pi x R2 x Ht x 7.48) |
| 6 | 3 | 9 | 3.1416 | 1.0 | 28 | 7.48 | 211 |
| 6 | 3 | 9 | 3.1416 | 1.5 | 42 | 7.48 | 317 |
| 6 | 3 | 9 | 3.1416 | 2.0 | 57 | 7.48 | 423 |
| 6 | 3 | 9 | 3.1416 | 2.5 | 71 | 7.48 | 529 |
| 6 | 3 | 9 | 3.1416 | 3.0 | 85 | 7.48 | 634 |
| 6 | 3 | 9 | 3.1416 | 3.5 | 99 | 7.48 | 740 |
| Diameter in Feet | Radius in Feet(R) | Radius Squared(RxR) | Pi | Water Height in Feet(Ht) | Total Cubic Feet | Cubic Feet per Gallon | TotalGallons(Pi x R2 x Htx 7.48) |
| 5 | 2.5 | 6.3 | 3.1416 | 1.0 | 20 | 7.48 | 147 |
| 5 | 2.5 | 6.3 | 3.1416 | 1.5 | 29 | 7.48 | 220 |
| 5 | 2.5 | 6.3 | 3.1416 | 2.0 | 39 | 7.48 | 294 |
| 5 | 2.5 | 6.3 | 3.1416 | 2.5 | 49 | 7.48 | 367 |
| 5 | 2.5 | 6.3 | 3.1416 | 3.0 | 59 | 7.48 | 441 |
| 5 | 2.5 | 6.3 | 3.1416 | 3.5 | 69 | 7.48 | 514 |
Metric Conversion
For those users who are more accustomed to metric dimensions, the following can be used with the previous tables:
To go directly from dimension in meters to liters, measure all dimensions in meters and multiply by 1000 to get liters.
For intermediate steps, use the following:
Measure all dimensions in meters and multiply by 35.1 to get cubic feet.
Multiply cubic feet by 7.48 to get gallons.
Multiply number of gallons times 3.785 to get liters.
As an example, consider a rectangular trough of Length 2.5 meters, Width 1 meter, and Water height .5 meters:
Volume equals 1.25 cubic meters (2.5 x 1.0 x .5 = 1.25)
or 44 cubic feet (1.25 x 35.1 = 44).
44 cubic feet is equal to 330 gallons (44 x 7.48)
or 1,125 liters (330 x 3.785 = 1,125 or 1.25 x 1000).