Pond and Waterfall Calculations

Figuring out what you need to build your pond is an important factor to determine it’s cost and efficiency.  The following guidelines should help you. Ask for help at thepondpad@gmail.com

                          How to Estimate Gallon Capacity

Circular Pond: R2 x 3.14 x Depth x 7.48 = Approx. Gal. R2= Radius x Radius (Radius is ½ of the total length)

Irregular /Rectangular Pond: Length x Width x Ave. Depth x 7.48= Approx.Gal.

Irregular Pond w/shelves: Length x Width x Depth x 7.48 x .66= Approx. Gal.

Streams: Length x Width x .25 (Depth) x 7.48= Approx.Gal.

How to Calculate Pond Liner Size.

Length= Length + (Depth x 2) + 2      Width= Width + (Depth x 2) + 2

Example: 8 x 10, 2′ deep L= 10′ + (2×2) + 2= 16′ W= 8′ + (2×2) + 2= 15′ 

                                    Electrical Conversions / Consumption

WATTS= Volts x Amps AMPS= Watts / Volts 1HP= 745.7 Watts

Approximate Electrical Cost to run a pump, etc.

Amps x Volts x 1000 x .10(KW per hour) x 24hrs x 30.4 days=$ / month

                           Aquatic Plant Calculations

Water Lilies: 1 per every 45-60 Sq F

Marginal Plants: 1 plant per every 3′-4′ shelf margin

Bog Plants: 1 plant for every 2′ of bog


                            Rock Calculations- For Gravel & Boulders

Boulders for Pond Basin:

Length x Width / 65 Tons of Boulders Use a 1:2:1 ratio

For every 1 Ton of 6”-12” rock; get 2 Tons of 12”-18” and 1 Ton of 18”-24” rock

½ Ton of 6”-12” of rock will cover 20 linear feet

1 Ton of 12”-18” of rock will cover 10 linear feet

1 Ton of 18”-24” rock will cover 5 linear feet

Boulders for Stream– For every 10′ of Stream, Use 3/4 Tons of rock using ratio above.

Boulders for Waterfall– Use 1 Ton of rock per each 3′-4′. Choose some larger stones for support, and some rocks with flat or interesting faces for the waterfall.

Gravel for Pond Basin– Use 40% total tons used for pond boulders calculations

Gravel for Streams– Use ½ Ton for every 10′ of stream

Pondless/ Disapearring Waterfall– Length x Width x Depth = Cubic feet

Use 90lbs of rock per each cubic foot; Use Ratio of: 40% 4”-6” Rock

(for the bottom of the basin) and 60% of 1 1/2” – 2” rock (for middle and top layer). Add decorative gravel / rock as a top dress.

These are guidelines to help you, always over estimate whenever possible. Any left over rock can be blended into your surrounding landscape.

www.alpinegrows.com         www.thepondpad.com

When to Clean Your Pond

by Kerri Bailey, The Pond Pad

It’s that time of the year again, when our ponds wake up from the warmth of spring with active fish and budding plants. Now is a great time to take a look and decide what condition your pond is in & what you need to do about it.

Your pond or water feature needs to be cleaned when:

  • There is an inch or more of sludge build up on the bottom and shelves.
  • Excessive algae blooms and filamentous(string) algae problems.
  • Your water is turbid, cloudy and mucky or slimy looking.
  • It’s been more than 3 years since the last complete clean-out.

How often you clean your pond:

  • Typically once a year, or every 2-3 years depending upon your fish load & filtration – heavier the fish load (yearly), smaller fish load & better  filtration (2-3 years).
  • There are always exceptions, healthy water = healthy fish & plants.  Using beneficial bacteria products like Autumn Leaves Digester by Strata, will help maintain the balance by digesting the fish waste & debris that accumulate over time.  Having a veggie filter, bog garden or just a lot of plant coverage will also enhance water quality.  Most algae blooms are a result of excess pond waste, so decrease your waste, decreases the algae.

When to clean your pond:

  • Water features, ponds, etc. with no fish- clean just about anytime of the year.  If there are plants, protect them from the hot sun or cold winds.
  • Typically, ponds with fish, are cleaned in late spring through early to mid summer, weather dependent (around 60 – 80 deg F). Avoid cold days, extremely hot days or when fish are dormant. Fish can die from stress, so be careful with them!

To learn more about cleaning your pond, see my blog on How to Clean your Pond  and attend one of my classes at The Pond Pad on Sat. April 7th and April 14th at 10am or Sun. April 8th and April 15th at 11am.   www.alpinegrows.com/pages/pondpad.asp

Kerri Bailey is the owner of The Pond Pad water garden store located inside of Alpine Nursery in Puyallup, WA.  Kerri has been working with aquatic plants and herbs since 1989 and has been in the horticulture and water garden industry since 1998.  She holds a BS in Biology and is a Certified Herbalist.