Another newbie: Pond planning

ddeuermeJune 16, 2014

I have a contractor redoing my entire landscaping, including adding a small pond. I've spent hours on the internet trying to learn everything I can about ponds to make sure the pond is installed in a way that I can enjoy it instead of constantly fighting it.

I'm in the western suburbs of Portland, OR. Zone 8. The pond will be about 5 feet in diameter with steep sides and 3 feet deep. The steep sides and depth are on recommendation from local pond shops to protect the fish from predators. I plan to have a few goldfish - most likely shubunkins and comets.

I've asked my landscape designer to add a shallow area, probably 18 inches deep to make it the pond look more natural and to give me an area for plants the prefer shallower water.

It will be in a sunny location. I read the recommendations about using plants to create shade to try to control algae.

I will have a 1500 GPH biofilter and a waterfall.

I still have a few questions:

The landscaper is planning to run an extension cord through a conduit under the new patio to plug in the biofilter/waterfall. Will I be better off having an electrician run a conduit? The pond will be about 10 feet from the nearest electrical outlet on the back of the house. I'll have a patio between the outlet and the pond.

I don't have plans to have a skimmer installed. The pond isn't under any trees. Will I regret not having a skimmer? If I decide later that a skimmer is a "must have," will I be able to install one without too much difficulty later? My yard isn't large, so I'd rather not take up the extra space if I don't have to.

I'm not having a UV light installed right now. From everything I've seen/heard it isn't difficult to add one later. This goes back to my potential need for an electrical conduit. Is it likely I'll want a UV light? It also looks like the light would only be turned on for a couple of weeks at a time. When not in use, do you remove the light fixture entirely and store it, or is that impractical to do?

What else do I need to think about? I'm trying to cover all of my bases now, before everything is installed.

Thank you for any advice!

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Holly_ON(6a Ontario)

My concern is that your contractor is doing your "entire" landscaping. Please make sure that he has extensive pond building experience. You don't want to have it redone by a pond building specialist in a short time. Doing it right the first time may cost more but in the long run saves a lot of money and frustration. (Learned the hard way) Extension cords are not usually recommended but make sure you have a GFI outlet at the very least. Plan ahead with more outlets than just the pump. You may decide on decorative or UV lighting etc afterwards. For safety, I would want an electrician involved. I would want the skimmer and the easiest time to put it in is during the initial build. The skimmer can house the pump so that your hose is hidden or you could look into an external pump/filter to clear the inevitable debris. The biggest mistake that people make is that they always wish that they had made it bigger. My current pond (three ponds later) was built by a specialist and I now can cut my remaining grass with a whipper snipper! The maintenance is less time consuming then grass was and enjoyment far greater. Caution - this is addictive!

    Bookmark   June 16, 2014 at 4:53PM
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Thanks for the information! I have been a bit nervous about having a landscape company do the installation instead of a professional pond company, but the landscaper has done water features before, including ponds and streams with waterfalls, and their pictures look beautiful! I've seen online pictures from some so-called professionals that don't look as nice as theirs.

Sometimes, I still get worried about having them do it, but every time I ask a pond question, my contact person at the landscape company seems to have an answer that I can validate online or with a local pond shop. He's the one who told me that the pond will need to be in a sunny location for good results with plants, that I don't want it to be right under trees, that I'll need to be concerned about algae, and that if I want fish, I'll need a good biofilter, and he seems to have selected an appropriately sized biofilter. I calculate my pond will be around 550 gallons and he wants to install a 1500 GPH filter.

I just sent him a message asking about adding a skimmer and he responded almost immediately that he can add one, along with the price of a "good" skimmer and the installation for it. That increases my comfort level quite a bit, too.

I have an electrician coming this week for other things, so I'll show him the plans and get an estimate for a conduit.

I don't think my pond can get bigger (I know, famous last words!). In this case, my yard is small and my grass area will only be about 5 x 10 feet already - just enough to add an accent area and a place for the dog to pee. I don't know where the pond would expand, unless I want to put on waders to walk through the patio door, or give up the grass altogether, and I think my dachshund would have a problem with that.

Just another couple of weeks before the demolition of my existing yard begins.

    Bookmark   June 16, 2014 at 5:44PM
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waterbug_guy(Phoenix AZ (Melrose))

I wonder if you only heard "extension cord"? An extension cord is not to code and not desired. However, I've often installed small ponds using conduit and run the pump cord thru the conduit to the outlet. Pumps can come with very long cords, 15'. Running the cord thru the conduit keeps everything neat and safe. Your contractor could get away with no conduct and just bury the cord because most are rated for burial. But conduct makes it easy to replace a pump later. Tie a string to the male plug, pull the pump out and the cord out thru the pond. Untie the string, tie onto new male plug and pull the string thru the conduit along with the power cord. Sounds like a good contractor and I can count on one hand the number of times I've said that.

Having an outlet next to a small pond is something I try to avoid. They're a little hard to hide imo. If the pond is changed later it often has to be moved. But OK if needed.

Now for the myths...and there are many. I'm assuming you'll have a few goldfish and aren't planning on koi. 5' diameter, 3' and you want simple. Good news is simple is also the easiest way to keep a pond. People on the web are bored and like to make pond keeping as complex as possible so they have something to talk about. Retailers like complex as possible so they have something to sell, and boy do they have stuff to sell.

1. If you're in a retail store to buy anything other than feeder goldfish or food you are going to make your life very complex.

2. Steep sides protecting fish from predators is a myth. It only sounds good and for many people that's good enough. Raccoons can pin a fish to the side vertical pond wall no problem. Herons, including Night Herons, have no problem jumping into a pond after fish or taking one on the wing. Plenty of YouTube videos showing that and I've seen Great Blues do it in an 8' deep pond (was a pool).

3. Marginal plants do not need to be submerged. When the label says submerged 6" or 12" they're taking about the max depth the plant can take. All marginals do much better in damp soil than submerged. And your life gets much easier too. String algae will often grow in and around the plants and getting it out is pretty much impossible. With no plants in the pond pulling out string algae is very easy. Plant pots on a shelf don't stay on a shelf. Little wind and over they go, dumping stuff all over your pond. And pots are raccoon magnets because looking under rocks for food is what they do for a living. If picking pots out of your pond every few weeks and trying to get the soil/media out doesn't sound like fun I concur. Water lilies and floating plants are the only plants that have to be inside the pond. In general these don't have the raccoon and algae issues. Completely submerged plants also, but these make life harder for you.

4. Plants do not add O2 to the pond, at least in any meaningful way. They consume O2 at night so the net result is water O2 is higher without plants. Not saying you shouldn't add plants, I'm saying adding them to increase O2 is a myth. Water Gardens are fine with plants because they don't have high fish loads.

5. Bio filters are almost never needed in a Water Garden. There are few enough fish that the pond by itself is bio filter enough. But buying an ammonia test kit is a good idea. Seeing a growing level of ammonia that isn't explained by water changes is when you need to consider adding a bio filter. Bio filters are easy to add later.

6. Mechanical filters (pads, sponge, etc) are pretty much worthless. Yes they will collect crap, and it does look like a lot when you clean them, but 99% of the crap stays in the pond. Way more effective in your size pond to just use a net and scoop around the pond bottom every week or so in the summer. You'll remove more and stir the bottom which helps break down small stuff. Emptying a new is sooooo much easier than cleaning these crappy filters sold to new pond owners.

7. Pumps are not required, but are very nice to have and does improve water quality.

8. Skimmers aren't just for leaves. Water surface tension allows dust to settle on the surface. It can make the water look dull. Skimmer fixes that. If you have a water falls it can produce foam on the surface and a skimmer helps reduce the build up of foam on the water.

I like a catch basin under the fall to totally eliminate foam and makes the surface still for better fish viewing. Personally I think a skimmer is a good investment. I build my own so I can place the pump behind the skimmer basket for the basket acts as my pre-filter. I like the pump up high. Easier to check and a pump on the bottom can drain a pond if something goes wrong.

9 Shade does indeed reduce algae growth...but not enough that you would notice. Whether it takes 20 or 22 days for string algae to become a problem doesn't really matter. Or whether a pond is sea green or forest green doesn't really matter, the pond is still green and unacceptable.

  1. You didn't mention it but plants also don't use enough nutrients to starve algae to death. Adding plants increases the amount of nutrients in a pond in almost every case thanks to the soli/media/fertilizer we add. One good thing plants do normally bring is string algae. Algae species battle each other different ways and one is by producing chemicals that make the water toxic to some other species of algae. They're why clear ponds stay clear although they almost never get the credit.

  2. UV filters are sized to keep a clear pond clear. If you wait until the pond is green you might need a bigger UV, although with a bypass and slowing the water thru the UV they can often clear a pond. The most likely time you'll get green water is during the initial startup. If you can get some plants into the pond, even if only temporary, string algae will likely come along for the ride and maybe get the upper hand and be able to stop green water algae from ever getting started. That's hit or miss. Green water algae also produces a chemical to kill string algae so the plants have to be there when water is added. But if you don't want to screw around a UV is your best investment. They can often be turned off after a month or two. The UV kills the green water algae so no chemicals to stop string alage (actually all macro algae) from getting established. Macro algae will appear on its own, spores float in the air, but can have a difficult time growing in green water. Waterfalls can help macro algae establish even in green water sometimes.

UVs can just be turned off. In some climates there are sometimes special instructions. When starting them up after being off for awhile it's a good idea to remove the glass sleeve that has the bulb inside and make sure that's clean. Also, these glass sleeves can sometimes cloud over, like a lime deposit but it isn't lime. This can happen after just a few hours of use. It's rare, but if water doesn't clear it's something to check. It's easy to clean off and surprising doesn't seem to repeat. I've only seen it once.

The most important advice I give is to not believe the most popular "facts". We live in a much different age than even 20 years ago. There used to be a filter on info. Now everyone's fantasy is presented as fact. It's getting harder everyday to wade thru the mountains of crap info. I think it's actually probably impossible. And that is by far the biggest cause for ponds to be filled in.

    Bookmark   June 16, 2014 at 6:17PM
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Holly_ON(6a Ontario)

A word of general caution to other newbies. Ask to speak to references as well. Ask what problems if any they encountered after the build and if the contractor followed up with problem solving. Do they offer yearly maintenance programs? (NB to me as a senior) What happens should you have a pond emergency such as a leak or pump failure? It is easy to put together pictures of ponds that the contractor likes but didn't necessarily build himself. Sadly this has been done. Collect pond pictures yourself of the ones you like so that you and your contractor can sit down together and are on the same page as to type of rock, look of waterfall style, edging expected etc. I congratulate you for doing your own research.

    Bookmark   June 17, 2014 at 8:06AM
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To add to the word of caution: use the internet well. It's easy to see if there are any BBB complaints and it's easy to look for online reviews, and to see how long a company has been in business.

Thanks for the wealth of information Waterbug_guy! You spent a lot of time typing that up for me and I am very grateful for your time and for everything you gave me to think about. I do want simple and I love that you told me simple is possible and I can disregard a lot of the complex stuff I've been reading online. It sounds like I'm mostly doing the right things.

I'm adding a skimmer and an electrical conduit to the original plans. It sounds like it's easy to add the UV lights, correct? If so, I'll probably add that myself later. At the moment, I'm thinking this will be more water garden than fish pond, so from what you say, I probably don't need the filter, but since i've never had a pond before, I know I could change my mind about what I want. I've also seen all of the messages here about baby fish. I could end up with a lot more fish than I plan to have, just because nature happens!

Since the rest of the landscaping is being done at the same time, I can ask for the conduit to be fairly low to the ground and located where it'll be hidden behind future shrubbery or close to the fence where I won't really notice it. I don't think it'll be a big expense to add it since the whole yard will be dug up already. I might appreciate the convenience later.

If plants on a shelf end up being knocked over anyway (Thank you very much for that information!), then what is the purpose for shelves? Is it just to make the pond look more natural? I asked for a vertical drop because of what the people at the local pond shops told me, I was a bit sad about not having the shelves for plants, but it sounds now like it would be a mistake to put plants on shelves anyway, so why are people so into shelves?

I didn't know that about adding plants when the pond is first filled to help combat algae. I'll change my plans a bit. I was going to let the pond sit empty until next year since it won't be completed until August. I didn't think the plants would look very good this year anyway. I'll get some to add right away regardless of how nice (or not) they look for this first year.

    Bookmark   June 17, 2014 at 2:24PM
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Holly_ON(6a Ontario)

Just a suggestion/another consideration....I would rethink the shelves especially since you have a dog with short legs. Plants can be anchored and you want the dog to be able to climb out should it fall in accidentally. Sadly a miniature poodle I knew well drowned in a koi pond with steep sides. This dog had end stage Alzheimer's, was disorientated and the very cold water was a contributing factor. Still, it was a heartbreaking way to remember a 17 yr old dog. My fish are more visible swimming on the shelves. They come for feeding etc. Once my plants became established, knocking over has not been a problem. Wildlife can also play havoc with plants outside the pond. In my neighbourhood, raccoons are the main predators. I've never seen a heron around here.

    Bookmark   June 17, 2014 at 4:10PM
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The dog, and other animals, are a concern. It's one of the reasons I've asked my landscaper to extend a branch onto his original plans to include a shallow area. Bella (my dachshund) hates water and she'll avoid the pond, but an accident would be heartbreaking and I probably would never be able to even look at the pond again. I also have two cats that also hate water, but my cats are old and will stay away from the pond. My neighbor has two young cats who are good fence-jumpers, and I can't rule out having other cats or dogs of my own in the future. I might need to ask for shelves in addition to the shallow area. I don't want to have to constantly worry.

    Bookmark   June 17, 2014 at 5:40PM
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waterbug_guy(Phoenix AZ (Melrose))

It sounds like it's easy to add the UV lights, correct?
Yes. But the correct term is UV filter when you go searching. A pipe has to be run from the pump to the UV and another one from the UV back to the pond. They make submersible models too.

I probably don't need the filter, but since i've never had a pond before, I know I could change my mind about what I want.
No bio filter is probably needed. An ammonia test kit will tell you if you need a bio filter. Bio filters convert ammonia that the fish produce into harmless stuff. Talk of bio filters comes from koi keeper and aquarists who have a real need for serious bio filters. In Water Gardens they aren't needed because of lower fish loads and having more algae which consume ammonia directly.

Mechanical filters remove dirt. But these require a very complex system to be effective. Scooping with a net is very effective for this in a small pond.

I've also seen all of the messages here about baby fish. I could end up with a lot more fish than I plan to have, just because nature happens!
I wouldn't worry. Nature also reduces.

I can ask for the conduit to be fairly low to the ground and located where it'll be hidden behind future shrubbery or close to the fence where I won't really notice it. I don't think it'll be a big expense to add it since the whole yard will be dug up already. I might appreciate the convenience later.
Make sure the conduit is large enough for the male plug, not just the cord. It takes a pretty big diameter. I think 1.5" PVC conduit works well.

If plants on a shelf end up being knocked over anyway (Thank you very much for that information!), then what is the purpose for shelves? Is it just to make the pond look more natural?
Personally I think shelves look very unnatural, but that's a taste thing. The purpose of shelves...I'd say to set potted plants onto. The idea has been around a very long time and is has been very common in design books, web sites. First time pond owners absolutely love the idea as many are gardeners. A shelf to add potted plants is very appealing. But once you start running into the problems they're not so appealing. Much of what you will read will seem appealing, that's why people keep repeating these things. They sound great.

Shelves are good for allowing animal egress.

If you like birds a 2" deep shelf is great for them. But there can't be cat ambush cover too close.

So there's nothing wrong with shelves, if you're OK with the look. The problem is the potted plants.

I didn't know that about adding plants when the pond is first filled to help combat algae. I'll change my plans a bit. I was going to let the pond sit empty until next year since it won't be completed until August. I didn't think the plants would look very good this year anyway. I'll get some to add right away regardless of how nice (or not) they look for this first year.
That is a great idea. Plus not adding goldfish right away makes your life way less stressful. You have more freedom to deal with any issues when there aren't fish.

But you might consider getting some mosquitofish. They'll take care of any mosquitoes so you don't have to worry about that. Plus I think they're very entertaining. You can check with your city to see if they will provide mosquitofish.

In addition to the ammonia test kit I suggest a KH kit. KH is related to pH and one very easy thing to do is test KH maybe once a month, or every few months. Keep KH up, like say 200 ppm (test kit tells you). You increase KH by adding regular plain old baking soda. Add like 1/4 or 1/2 if KH starts getting below 150 ppm and then test again the next day and add more if needed. The nice thing is you can't really add too much baking soda. Even crazy high KH number don't seem to affect fish. I wouldn't go crazy, but even 500, 1000 ppm KH is OK.

This whole KH thing is what's called a pH buffer. Ponds produce acid and rain is pretty acidic. This acid reacts with the baking soda and over time KH drops, but pH remains stable like at 8-10. But if KH gets low, say 20-40 ppm there's nothing much for the acid to react with and pH goes down fast, we call it a pH crash, which can hurt fish.

All this pH stuff can get very keep it simple. Just test KH once in a while and add baking soda as needed. That's it. Many people say to test pH but pH is really tricky, way more than many people think. KH is simple and then pH testing is never needed.

So 2 tests, ammonia and KH and you'd be ahead of most pond owners by a long shot.

    Bookmark   June 18, 2014 at 4:51AM
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waterbug_guy(Phoenix AZ (Melrose))

There is one pond keeping method I keep forgetting to mention that can reduce complexity a lot while increasing water quality to professional levels. And it's super cheap and almost no work. It has several names, "constant water change", "flow through", "trickle water change", "drip water change".

The idea is to have a slow drip into your pond from a drip irrigation emitter and an overflow. Once set up you can almost do nothing else. Issues with ammonia, nitrite, KH, pH etc., go away. People are reporting no green water (but this doesn't have a lot of data). DOC levels stay low (depends on your source water) so no foam on the surface. You never have to top off the pond and forget you left the water running. You never have to do an old style water change. It will remove a lot of suspended matter which will keep the water clearer and less muck build up. Super cheap.

How much water to add to the pond is a matter of opinion. Koi keepers say 10% per day and in Water Gardens 10% per week. This has to do with koi keepers having a lot of big fish and Water Gardens not having a lot of fish. In small ponds the minimum size emitter really determines the amount of water. A 5' diameter x 3' deep pond (no shelves) is about 400 gals. 10% a day max is 40 gal a day or 1.6 GPH. 10% a week would be 0.25 GPH. So your pond would need somewhere between 0.25 and 1.6 GPH. The smallest emitter that can be commonly found is 1 GPH so that's what I would use.

Your cost is about 24 gals of water per day, 720 gals per month. In the city of Portland OR that's about $3.40 per month. And the water from the over flow can be directed to landscape so it gets 2 uses in which case the water for the pond is free. But I'm not sure if you guys have to irrigate.

BTW, an overflow is handy no matter what. In areas with high rainfall letting a pond overflow at the edges can cause problems, including a floating liner. Also, if you don't add a drip water change system I suggest an auto fill. A float valve in the pond adds water when the water level drops, I supply the float valve from a sprinkler valve connected to a timer. Floats sometimes stick or break and I don't want a ton of city water going into the pond so the sprinkler timer limits that. Timer set for just a minute or two per day is enough.

For lowest possible maintenance and highest water quality for fish this type of system can't be beat. The biggest drawback is many self proclaimed pond experts have never heard of such a thing and certainly would never do any reading, they prefer to just repeat old crap so they sound smart. So you have to get used to having to explain the system and deal with charges of "the chlorine will kill your fish". But that's also a good way to determine if your talking to a blowhard. People actually into ponds will always have an open mind and will ask lots of questions to learn about how the system works.

Here are 2 videos that describe the how it works.
Doc Johnson and Andy Moo starting at 7:25 into video.

One additional tip for setting up the emitter. These emitters can blow off the 1/8" hose. Adding a pressure regulator to keep pressure in the hose low, say 10 PSI, helps reduce the risk. But I also don't point the hose and emitter toward the pond. Instead I bend (half loop) so the hose goes down into the pond and I bend the hose so the emitter is pointing up and away from the pond. The drops out of the emitter will dribble down the hose and fall off the hose at the bottom of the bend and into the pond. If the emitter should ever pop off the stream of water will shoot out of the hose and away from the pond. The stream of water shooting into the air will alert you to the problem. This can all be kept in place with some natural looking wood from the yard, like a tree branch.

    Bookmark   June 18, 2014 at 3:14PM
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I have to read through this more closely and look at the videos later when I get home - I'm at the doctor's office, but I'm very excited about what you said. My landscaper already inluded into an auto-fill in his plans. It's something I was forgetting to ask about. So I think if I just pull a few pails of water out after work every day to use to water my veggie garden, it'll probably be just about perfect. I'll have to look more at the overflow stuff. I can see where this might be something to plan for since it rains a lot in the winter.

I need to look more at the UV filters, too. it sounds like this might be something I want him to add up-front instead of messing with it later. I thought it would be as simple as adding the UV filter to the PVC pipe. I didn't realize it requred a long run of pipe to connect into a couple of places. I'll need to do some more homework on this.

    Bookmark   June 18, 2014 at 4:25PM
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waterbug_guy(Phoenix AZ (Melrose))

Sounds like you have a pretty good landscaper that they were already planning a auto fill, plus they knew about the conduit trick. That's above average. But make sure the auto fill is supplied by a sprinkler valve on a timer. It saves you from a flooded pond/yard and dead fish. But you don't need any auto fill if you do the drip system.

You also probably wouldn't need the UV with a drip system.

A UV doesn't require a long run of PVC, unless maybe if you mount it close to the electric. They also come as a submersible and a long power cord (15-20').

Overflow is pretty simple. A EPDM bulkhead fitting, less than $10 for a 1" and some 1" PVC pipe. The trouble with pulling out water with a bucket is you have to do it. When putting in a pond people can be very optimistic about what they will do in the future. Overflows make life simple and work 24/7. You can still use the bucket whenever you like. Even better is a putting a pump in the bottom of the pond with a hose and turning that on for a minute to water the landscape. That'll pull settled dirt out of the pond.

    Bookmark   June 18, 2014 at 8:09PM
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Thanks once again for the information! In the end, I decided to keep it all: biofilter, skimmer, and add a UV filter. I know it's probably overkill for a small pond/water garden, but in my circumstances, it seemed to be the wisest way to go. I'm a transplant patient and I'm not supposed to dig around in mucky things where potentially life-threatening bacteria could be lurking, so "success" to me means a beautiful pond while limiting my exposure to bad bacteria. It's worth the cost for me.

    Bookmark   June 27, 2014 at 11:49AM
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