New Ponds

What I Need to Know About, to Install a New Pond and Why

This is a guide, or check list if you will, for you to take home and study.

First Question, that you want to ask yourself is, “Am I skimping on the pond because of money?”. You want to budget about $1,000, for the pond. The reason for this is, because whatever you save on the pond itself, you’ll spend on rock and landscaping. Once you have made the money decision,

Second Question, is, Where am I going to put the pond? We will not put a pond in the front yard because of liability. You don’t want a young child who will be fascinated with the water feature, falling in the water and drowning. The choice is yours. You want to sit on the deck or back porch where you can see and enjoy the pond. You don’t want to put it back at the farthest point in the yard where you can’t hear the waterfall or see the pond.

Third Question, Do I have enough sun? You want about 6 hours of sun. But don’t worry if you don’t have enough sun or too much, we’ll just plan around it.

Fourth Question, Do I want a liner pond or a prefab pond? The liner pond gives you the opportunity to be creative in the design of the pond. Also it gives you volume, which is important in the health of the pond. We try to have a pond of at least 500 gallons or 4′ x 8′ (the size of a sheet of plywood), and an average 3′ depth, which will give you about 720 gallons.

These are the important questions.

Next are things to think about before you start digging.

Do I what a water garden or a Koi pond? Water gardens have plants and fish in them. Koi ponds just have Koi in them. One is not any better than the other. You may not want fish in the pond now, but you will get them sooner or later, so we’ll set up for them now when it’s least expensive.

Koi Pond – Koi ponds are deep. Usually 3″ deep with straight walls. Koi like lots of water and the water changing about 2-3 times an hour. An example is a 1000 gallon pond with a  2000 or 3000 gph pump running with an extensive detoxification filter on it. One thing that we have realized, when you dig a pond that deep you need to add a stair way out in case you fall in. We recommend that you put one at 18″ deep and about 24″ deep about 24″ to 36″ wide. Because it will be slippery. You can put rocks or plants on it so the heron can not use it to feast on.

Water Garden Pond – Water garden ponds are generally 25 gallons to several thousand gallons and contain plants and fish. The prefab ponds are usually 18″ deep and have one or more shelves in the pond. Some of the prefabs are 22″ to 24″ deep. With a liner pond you shape them any way you want. You put the shelves anywhere you want. Our recommendation is to put a shelf 12″ to 18″ deep and 18″ wide, that angles about 2″ to 3″ back to the wall of the pond. The reason for this is that most pots, or at least the pots that we use to grow our marginal plants in are 9″ to 12″ deep. You want the pot under the water. The next shelf is 24″ deep. This shelf is where your water lily’s will grow. The water lily shelf is across from the waterfall. Lily’s don’t bloom with splashing water. The final shelf is the bottom of the pond. It is 3′ to 4′ deep. This is where the pump will go, and it’s at the waterfall end. As the water falls into the pond and the pump is at the bottom it tumbles the whole pond gently, which is what you want.

Things to Consider

Liners – There are a lot of liners out there. We use Firestone “Pond Guard” which is 45 mils thick with a 20 year warranty.

To figure out how much liner you need, the formula for a 10′ x 10′, 3′ deep pond is:
Length x Width add 8 to each of the figures. Example 10 (+8) x 10 (+8) = 18 ft x 18 ft with 1 foot around the ponds edge and 3 feet deep.

Keeping this formula in mind, the liners come in 10′, 15′, 20′, 25′, and 30′ and so on. You want to figure the pond out so that you maximize the liner so you don’t have any waste. So, using our example, the liner closest to our size is a 20′ x 20′ liner. You can enlarge the pond to 12′ x 12′ and use all the liner. Let’s move on.

Now we have the hole dug and the liner in the ground. The next thing is to add or not to add a skimmer.

Skimmers – There are several types of skimmers. In wall (the most common), floating and tower. If you have a large pond, say 1000 gallons plus, or any size pond and it’s under or near trees, a skimmer makes you life so much easier. Depending on which skimmer you get, they can add from $70 to $500 to the cost of the pond. It’s a call you have to make if the project is getting tight. If it is not, a skimmer is a really good investment.

Now, the easy one.

Pumps Don’t buy a cheap pump. The old TV commercial, pay me now, or pay me later is very very true here. This is the most important formula that can EDUCATE you in the whole pond gig. “Amps x volts (115 or 230 volts) = watts x hrs per day of operation divide 1000 x cost per kilowatt hour”.

Most pumps already have the watts listed so…..

Example: 350 gal per hour. At about 85 watts, can’t mention the name. 1 year warranty. And costs $35.00 or there about. A chain store pump.

85 x 24 (the 24 comes from running the pump 24 hours a day, which you have to do) = 2040 watt hours divide by 1000 = 2.04 times .10 cents (which is the cost per kilowatt hour) if this is wrong, who cares, this number gives us a base line to compare the cost of the operation of the pumps. You can compare all pumps this way to see which pump if more efficient for you. The answer is .204 cents per day to run your pump. Cost is $74.46 per year. NOW take the same pump, different manufacturer, 3 year warranty, cost is $54.00, watts are 35 watts.

35 x 24 = 840 divide 1000 = .84 x .10 cents = .084 cents per day to run. That’s $30.66 a year. So you can see that spending the extra $20 bucks upfront, you’ll save $10 the first year and you’ll have another 2 years on the warranty. This is a no brainer.

Now that we can figure out how to price a pump, let’s figure out one for the waterfall.

All pump boxes show a few things, all of which are important in determining the size pump you need.

1st – How high is the waterfall going to be? The average is about 5′. Look at the box at head pressure, which is the ability for the pump to push the water at various heights. Water weighs 8 lbs/gallon.

2nd – How wide will the falls be? Let’s say 3′ wide, which is about average. We like to figure 100 gallons of water for every inch of waterfall width. That also figures 1/4″ thick of water going over the fall.

This figures out to 3600 gallons/hour we need to go over the top, so we need to look for a pump that will flow 3600 gph at 5′ of head. Piece of cake!

Next are the waterfalls…….

Waterfalls – However you want to do them is all right. Just a few things to think about.

1st – Make sure you have a piece of liner behind the waterfall to catch the water that leaks from the waterfall. Also overlap it in the pond at least 1′.

2nd – Flat stone or field stone, field stone is usually less expensive. Flat stone you can use just about any flat stone, except sandstone. Sandstone will fall apart with the water running over it and will shatter in the winter. Stone will cost you the most in the whole project if you have to buy it. When installing the stone you can do a couple of things. There is no particular way to do it, just do what is comfortable for you. That is, you either cement the stone, silicone, or if it’s flat stone, you can just angle the stone forward. Before you do any cementing or silicone put the waterfall together and look at it. You might be rearranging the rock a few times. The best and cheapest thing to do is to go on all the garden walks in the area you can find, and if someone has a pond in your neighborhood, just go ask them if you can look at it. People like to talk about their water gardens!

Tubing – The biggest problem I see with people when they buy tubing is they skimp on it. This is a product that can make or break a waterfall. The manufacturers don’t say on their boxes to oversize the tubing by 1 size. Example is that a pump that has a 3/4″ opening, that means you attach a 1″ hose to it. That gives you maximum flow. And don’t go to the chain store and buy sump pump tubing for next to nothing cost. That tubing isn’t made for this kind of use. It WILL spring leaks. With that in mind, we keep our tubing close to the surface so we can take it up in the winter. You can hide the tubing with mulch and planting at the back of the waterfall.

Here is a few figures to help on tubing and pump sizes.

Maximum recommended flow rates for flex & PVC tubing.

1/2″ 480 gph

3/4″ 900 gph

1″ 1500 gph

1 1/4″ 2700 gph

1 1/2″ 3600 gph

2″ 5400 gph

3″ 13500 gph

4″ 21000 gph

6″ 42000 gph

I hope this helps you on the beginnings of a great hobby. If you have any questions, you can reach me at and I’ll reply as soon as possible.