PONDS, PUMPS AND WATER PLANTS
Ideas and Tips

Q: What do I do about algae in ponds? Read tips.
Q: What size pump do I need? Read tips.
Q: How do I calculate pond volume? Read tips.

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Q: What do I do about algae in ponds?
A: There are several things you can do to reduce or eliminate algae in ponds. Pond plants can compete with algae for sunlight and nutrients. Keeping your pond clean is important. If algae starts growing, try the following:

• Use an algae blocker.
• If you have no plants or fish, use an algicide.
• Check your filtration system. Make sure it is adequate.
• Use enzymatic clarifiers: Pond Clarifier by Organica or PondZyme by PondCare.

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Q: What size pump do I need?
A: Generally speaking, at least 1/2 the volume of pond water should move each hour (so a 200 gallon pond needs at least a 100 gph pump). Waterfalls require 100-200 gph for every inch of spillway width.

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Q: How do I calculate pond volume?
A: You need to know your pond volume to determine the right pump, filter, water treatment, fish capacity, etc. To calculate your pond volume, the formula is : Surface Area X Average Depth X 7.5 = gallons of water.

Your Average Depth can easily be measured. Your surface area depends on the shape of your pond:

For a rectangle - Surface Area equals length times width.

For example, a rectangular 6' X 4' X 2' pond has a surface area of 24 sq ft (4' X 6'), an average depth of 2 feet, and a volume of 24 X 2 X 7.5 = 360 gallons.

For a circle: Measure the widest distance across. 1/2 of that is the radius, R. The surface area equals R X R X 3.14.

For example, if your circular pond is 5 feet wide and 2 feet deep, the surface area is 2.5 X 2.5 X 3.14 = 19.63, and the volume is 19.63 X 2 X 7.5 = 294.45 gallons.

For an oval: measure from the center to the farthest point (A) and the widest point (B). The surface area is A X B X 3.14.

For example, if the distances from the center are 3 feet and 2 feet and the pond is 2 feet deep, the surface area is 3 X 2 X 3.14 = 18.84, and the volume is 18.84 X 2 X 7.5 = 282.6 gallons. (Notice that the overall length and width are 6' X 4', but the volume is not the same as for the rectangular 6' X 4' X 2' pond.)

For a kidney-shaped pond: measure the longest point and the widest point of EACH end. The surface area is about 0.45 X length X (the two widths added together). So if your pond is 6 feet long, one side is 3.5 feet wide and the other 4.5 feet, and the depth is 2 feet, the surface area is 0.45 X 6 X (3.5 + 4.5) = 0.45 X 6 X 8 = 21.6 and the volume is 21.6 X 2 X 7.5 = 324 gallons.

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