Choosing a pump

When choosing the best pump for your pond calculate your head loss. Head loss is the vertical distance the pump has to push the water plus the friction caused by the water flowing through the pipes and fittings. If the flow rate is too high for the pipe's diameter, you create more pressure.

  Head losses also happen when filters clog with debris and create back pressure; this can be eased by keeping your filter clean. Too many elbows can add to back pressure. Pumping vertically, whether it is to a waterfall or a filter, will also increase head pressure. Running costs increase with head loss, so it is important to keep head loss to a minimum.

To read all my pond articles, go to Backyard Ponds with the Pondlady

Digging the hole

When you are digging your hole, dig straight down. If you dig a bowl shape you will slide down into the water every time you try to get in your pond to do maintenance. You also have more surface exposed to sunlight and that causes algae growth.

For pond information get my articles at Backyard Ponds with the Pondlady

My pond has air under it

When the water table rises and pond liners are floating up to the top of the pond, pushing the water out, you think that is air under your liner. Nope, it's water. 
If your pond was built 3" or 4" above grade, the weight of the water in the pond would keep the liner from bubbling up.

Nothing whatsover will keep that liner in place, so don't try putting rocks in the pond. It won't work. 
Here's what to do: Try to raise the edges. Build a levee around the pond and hope that you left enough liner to cover it. You can use most anything to build that levee.

I always use rocks on top of the edge of the liner, curl the liner up and over that course of rocks and then cover the whole sandwich with another course of rocks. You can see the 'how to' with photos at
How to build a pond

For all pond articles catalogued, see Backyard Ponds with the Pondlady

Pond hardware

So often when we are buying hardware for pond fittings, we buy the first ones we see or the cheapest.

When you are buying hose clamps, don't buy the cheap ones...they rust and fall apart. Buy the more expensive steel ones. They will last forever. Same with plastic hose fittings. Buy brass hose fittings. You will never need another one.

Liner damage

Always cover your liner with rocks or water. Liner exposed to the sun can incur damage quickly. Rubber or EPDM liner lasts much longer. Exposed plastic liner, either flexible or a preformed shell will crack in a short time and it cannot be repaired.

Making the pond bigger

I want a bigger pond. Can I just glue a new liner to my old one?


Pondlady sez:
You will have disastrous results if you try to make a pond bigger by seaming liners.
You simply cannot seam liner in the field.
 Try building a second pond right next to the first with a soil wall in between. Use that space for a walkway or a waterfall, maybe two. You will need a second pump, of course. But the two ponds will look like one. This is a much cheaper and easier way to get a bigger pond.

Here's one that I did.

preformed v. liner ponds

I live in Memphis, TN. I am considering putting a
pond in my back yard---possibly this weekend if I get real energetic! 
My question is this, my neighbors across the street purchased a preformed
pond, another friend of mine has a liner type---do you know if one is better
 than the other?

Pondlady sez:

 Use a flexible liner. Never use a preformed pond unless you have no choice. It is a major hassle and will never look right because you cannot get it level. If you do use a preformed pond, only dig it in to the shelves and either put soil to the top or pile rocks to the top. Cantilever rocks over the top so you hide any trace of the plastic. Plant around it to soften the hardness of all those rocks.

More letters

Mark from Florida writes:
I saw something on T.V. the other day and I thought you might know where I can buy it. The best way to describe it is it looks like a big (about 18 inches wide) harmonica. A single hose connection goes in the back and water comes out multiple holes in the front. Appreciate any help - thanks.

Pondlady sez:
I have never heard of it, let alone seen it. It sounds like a simple manifold and would be easy to build yourself. I have had some experience with 'prefab' waterfalls and pipes or fountain heads with holes in them and very often the holes will clog up. Pretty soon, only one hole is left unclogged and is shooting water out of your pond. It can drain your pond and drive you crazy trying to keep the holes clear.

Letters, we get letters

Dear Pondlady,
I want to use heavy duty visqueen for my pond. It's cheap and I don't see why it wouldn't work.
I also need to know how many gallons I have so I know what pump to buy.

Pondlady sez: 

Use 45 mil butyl rubber liner. It is fish friendly and will last longer than 6
mil plastic. The visqueen will tear while you are putting the pond together. The rubber liner comes with a 10 year guarantee at the very least, usually 20.
Gallons of water are figured like this: length x width x depth x 7.5 gallons per
 cubic foot. The proper pump moves half the water every hour, so knowing how many gallons you have leads you to the right pump. Larger pumps than necessary are great because they push more water over the waterfall.

Spring questions

I get questions via email constantly. I like to feature the most common ones so all can see.

Here's one I get often:

Hi Jan,

I love your site and hope to ask a question specific to our pond. Can we avoid changing out all the pond water in the spring, as is recommended for most ponds in the spring? We live in Westminster, Maryland and have a 3' x7' x10' pond with liner to 2' depth, then stacked landscaping stones to surface and above to the bank. It is an awful lot of water to exchange for spring maintenance (more than 1200 gal) and the habitat is very healthy - 15 koi/goldfish and aquatic plants. We use an ultraviolet clarifier with regular filter ( no biofilter) and a separate pump for the waterfall. In December we removed them down for winter.

Could we simply start up the pumps, filter and uv system in the spring to get things rolling instead of exchanging all that water? I know we'd have to clean our filter almost daily for a period, but don't mind. I'm afraid to shock a healthy ecosystem, but not sure how to proceed.

It's our first spring with the pond and I don't want to mess things up!

Thanks so very much!

I think you can get away without a full water exchange. Use an enzyme like Microbe Lift PL
to get things started when the temps hit 55ºs day and night. First pump out about 25% of the water, put the Microbe-Lift in. Start up your pump/UV/filter. Repeat the following week. If you do this 4 times, you should be fine. If you see lots of gunk at the bottom, you have to get it out of there before it starts to release ammonia as the weather gets even warmer. You may need a pond vac
to get it out of there. I like it as well as any of the vacs even tho it is not perfect.

Pump that water into a veggie or flower bed because it is great fertilizer. Don't forget dechlor every time you exchange water.

Mardi Gras

Mardi Gras was yesterday in New Orleans. It was early this year and this gardener, for one is glad it's over. We saw 80º weather yesterday and probably 60's today. It is time to think spring for pondkeepers in the South.
Before your pond water starts getting cloudy and threatens to get green, use barley straw either in liquid form, bales or pellets

Either of these products will keep your pond clear through spring and summer.

Southerners: Something to start thinking about: If your pond has debris on the bottom and your pond plants are brown rotting before spring growth, it's time to clean your pond. The fish are still dormant as are the plants, and the weather has not yet reached the 90's of the summer.

Birds need a bath

Here in New Orleans, we are in the midst of Mardi Gras partying that all stops at midnight tomorrow, Fat Tuesday, the day before Lent.

This time of year, our temperatures begin to warm and birds begin their migrations north. This swamp bird has all the water he needs in which to bathe and they do like their daily baths. If you are not near water, try to provide water for your birds to drink and bathe in.






If you are like me, daily changing of bird bath water is something that sometimes does not get done. A solar powered birdbath keeps water constantly flowing in the basin and through a hidden reservoir, so birds can enjoy their daily bath.

Water Gardens International

Water Gardens International

This is a great online organization. I have found wonderful articles in here about water gardening around the world, informative articles about water lilies and such. Good place to cruise around on these cold winter days.

Northern Ponds

I was going to talk about airstones for you folks in the North. You had a bit of January thaw, so an airstone could have been a good idea to introduce some O2 into your water. When the next thaw hits, think about throwing an airstone in the water. Now you are back in the midst of cold and wind advisories, so be glad your fish know how to take care of themselves and you do the same.

Southern Ponds

Days are starting to get longer. In the South, ponds are beginning to know spring is coming. If your water is getting cloudy from sitting in the cold weather for so long, it's a good idea to give it a good start for spring and avoid an algae bloom if the weather unexpected warms up. Try Microbe-Lift Nite for use in colder water to give your pond advance protection against unexpected nitrification.

Feeding your fish

Here in the South, although we are having some cold weather right now, we often have 70º+ days. When this happens, you will probably go outside and check your pond.
Your well trained fish will see you and come to the top of the pond. When you see them, you think they are hungry. Please do not feed them. Their metabolisms are still slowed down almost to the point of dormancy and they cannot digest food. If you feed them, they could die trying to eat. Even if they don't eat, the food will fall to the bottom of your pond, rot and create big problems for you and your fish when the weather does warm.

Don't feed your fish until temps are consistently above 60 degrees outside. Day and night.

For pond supplies, check out The Pondlady's Shop

And to read my pond articles go to Pondlady's articles

Spring is right around the corner. Make sure you have the supplies and equipment you need to start another year of enjoying your pond.

Ice on the pond

In some parts of the country, ponds are frozen over. If yours is, you must open a hole so gasses can be exchanged. Do NOT hit the ice with a hammer. You can kill your fish if you do. Run water over the ice or put a pot of boiling water on top to open a hole. You can also buy a de-icer if you like at The Pondlady's shop


Don't forget to drop in and say "hi" at Gardeners Gumbo
We have a great time talking about gardens, garden crafts, junk, totems, or most anything.

What happens when it rains?

I was often asked if a pond would overflow if it rained. I suppose so, but the water would only go into the surrounding landscape. I ran into many ponds with an overflow pipe built into them. These were concrete ponds and to me, that was just an extra expense and unnecessary. If the pond is going to overflow, let it. Now a flood can be a different story. If your pond floods like ours did in New Orleans after Katrina, you fish will probably swim away and you may lose your plants. But your pond will be OK.
If your pond is build at grade, you could have problems because all those chemicals and fertilizers and run off will end up in your pond when the rain stops. If your pond is built the way I recommend, about 4" above grade, then you will be fine.

Large pond pumps

When a pump moves over 3000 gph, it is a large pump for waterfalls where you want lots and lots of drama. I love large pumps and used them for almost every pond I built. My customers loved huge waterfalls like this one.




A large Oase submersible pump can move 3000 gph and would be great for a huge waterfall. It has great warranty and costs very little to operate.


This Little Giant pump is an in-line or external pump. It moves even more water, takes less maintenance - you don't have to get in the pond to clean it, costs even less to run because it does not have all that pond sludge clogging up the impeller.

Medium sized pumps

Medium sized pumps are normally used for spitters or fountains

The head will usually be from 300 gph to 660 gph, with the larger one used to get the water higher or stronger. Be careful with spitters and fountains because if the water shoots too far in the air, it can splash out of the pond and soon you have pumped your pond dry.

For medium sized pumps, I like the Little Giant 350 gph

Just be sure to keep the impeller clean on smaller pumps for longer life. They usually need to be cleaned once a month if you feed your fish.