Pond Boss Forums INTRO New Forum Member Introduction New Member: Constructing a Natural Swimming Pond

Hi!

I am new to the forums here. I've been doing a ton of research because my hubby and I are renovating a farm pond to create a natural swimming pond. While a search here yielded nothing on this topic, the basic goal of a natural swimming pond is clear water via a healthy balanced ecology, so I figure there's lots that you all can tell us!

We bought our farm in 2011. It had been abandoned for thirty years and has two large ponds (both spring fed) as well as three spring boxes (one of which is our water supply for the house). In 2012, we had the upper pond breached and dredged with heavy machinery and then, in 2013, we bought sheep so we put a fence around it. (Sheep will drown in ponds with clay sides that are steeply sloping, and besides, we really wanted to make the upper pond into a family swimming hole, since we have such an abundance of water, and the lower one into a fishing pond.)

We were advised to put ONE grass carp in each pond, to help keep pond weeds down. We did that. Then, in 2013, we decided (before fencing both ponds) to dredge the lower pond as well. It was February, and our excavator found the large grass carp in the mud and put it into the upper pond, so it would live. Our understanding was that both fish were sterile.

But, of course, they weren't. As a matter of fact, it seems that we have two kinds of fish in this pond: some kind of orange, koi-like kind and some silvery ones: more like grass carp. Whatever they are, they do eat all the weeds but they also churn up the mud constantly. So, last summer and this summer, there have been baby fish in our upper (erstwhile swimming?) pond. The water snakes came in after the fish, and the multiple fish also constantly stirred up the bottom so the thing looked like muddy green yuck this summer. Added to that, two years of sedimentation without much clean up or care on our parts (we've been busy with other things) and stagnant water have resulted in a place that is none too inviting for swimming!

We kicked around the idea of not fighting nature, but just making it a real fishing pond, and building a modern, chlorine swimming pool, but the costs are way beyond our reach. I did some 'net surfing and would up researching natural swimming ponds--very common in Europe, but little known here.

This article is a good start in case you wonder what I'm jabbering about here: Mother Earth News: DIY Natural Swimming Pool .

The idea is that you create an internal barrier in the pond, which reaches vertically from the bottom of the pond to within 2" of the surface, using something rigid like stone or wood and a liner (if you aren't lucky enough--as we are--to have a clay-bottomed, established pond that is spring fed and therefore never lacks water at a level set by the overflow). This central zone for swimming is connected to (and usually rimmed by) a "regeneration" zone, reserved for plants, which because they are planted on crushed rocks, naturally clean the water by removing nutrients and thus starving algae into submission. You also rely on aeration, and some swimming ponds have circulation pumps, UV sterilizers, and skimmers. (In fact, purists among the NSP advocates get pretty shirty with these later additions, saying that they are no longer natural, but that's outside the scope of this post. :D)

The pond's internal barrier both defines the swimming area and keeps the plants in check, since you grade the gravel in the plant area from the shore downward on a slope to meet the barrier at a depth of about 18"-2'. The gravel is supposed to provide lots of surface area for aerobic bacteria. If you aren't going to augment circulation with an electric pump, then you need a 50-50 surface ratio between your swimming and regeneration zones; those with more technology can get along with a 65-35 ratio. Our pond will have the 50-50 ratio, since we don't have electricity near the pond.

However, we have decided to purchase a windmill-driven aeration system from Koenders. It will have two air stones, which we'll place at extreme ends of the elliptical swimming zone of our pond. Our plan is that the plants and the aeration (along with possibly some muck-eating pellets added this winter to help the aerobic bacteria clean up the 6" of muck that's accumulated in the past two years) will result in a clean, fish-free swimmin' hole next summer.

Note that I said "fish free." We have had a long, dry summer, and it seemed like it was "now or never" for this project, so we've been draining the pond for a week using siphons. Our pond measures 80' X 50'. We're down to about 18" of water, and this week it's "catch all the little fishies."

Which leads me to my first question of this thread.

One disagreement that my hubby and I have is whether or not it's reasonable to think that we can catch all the fish? (Full disclosure: hubby thinks that we can drain all the way down to the muck, and leave them high and dry, and I think that our siphon will give out before then, and want to put enough table salt into the few inches of water that I'm sure will remain so that all fish that we can't catch--and any eggs--die from too much salinity.) Sad for the fish... but I can't help it. We'd love to hear what others think of our chances of catching all the fish/fish eggs, and how you'd go about it if you were us. (Would minnow traps work, for instance?) I'd love to be humane about this!

The second opening question is this: we have some piping through out dam: it's a 2" PVC that we had put there when we breached/redid the pond, and (miraculously) it doesn't leak. My hubby wants to plumb this into a sump of sorts at the lowest part of the pond by buying a plastic tub (large), sinking it to the lowest spot in the pond, running shallow ditches to it, and bulkheading it and then plumbing it such that we can, next time, drain the pond faster than the current method of having three 3/4" hose siphons running. He would plan to cover the tub with 1/4" mesh to keep it from getting clogged, and plumb PVC (glued) on the other side of the dam down our hill so that it's outlet is below the pond bottom, with a ball valve, so that he would have a simple siphon. Anyone tried anything like this with a pond as big as ours? Mistakes made and lessons learned? Cautions?

I have many pictures to share: this is a fun project and I'm doing a photo essay on it. I'll put up a few here on my next post.

Welcome to the forum!

Instead of salt, look into using Hydrated Lime to kill any remaining fish in the pond bottom. No, you can't catch 100% of the fish. Maybe 99.9%, but all it takes is one pair of fish.

I'd think about putting some Fathead Minnows in the plant portion of the pond. With all the plants, you won't have much of a water current on the top of the water among the plants. What will prevent mosquitos from laying eggs and hatching larvae?

I would also recommend using and electric pump to aerate the pond. Much cheaper and more effective. Read posts on aeration. Bill Cody has great connections here. You can run air tube from the house for very cheap.

I agree about mosquitos. nothing will ruin a swimming hole faster. Minnows are way better. Gambusia "mosquito fish" have done well for me.

Well, we've already ordered the windmill, so we're committed there. We don't want the electricity costs, and the labor of burying the line, and it seems that our pond is way undersized for the windmill's capacities. The house is 400 feet from the pond. I had read how that can be done (compressor near house for electricity and then air line to pond), but the windmill seemed like a one-time, up front investment in maintenance-free and somewhat constant aeration. (We've read about people putting compressors on timers anyways, and here in the mountains of WV, we get a pretty steady breeze year round.) I hope it's the right choice! We'll see.

The aeration will provide some movement to the plants over top of the barrier; so will convection currents due to temperature changes (warm water flowing down as cold water sinks), and general water flow through the barrier, since we are planning to construct a non-standard barrier (more on this below). At least, that's the theory.

We have bats that eat mosquitoes and there will be frogs and salamanders and dragonflies. We have VERY few mosquitoes here and, remember, the whole pond has been stagnant for years (both ponds, actually) without increased mosquito populations, so we don't THINK that's an issue.

The fish, if present, wouldn't stay in the plant zone. It's fluid between them. The design includes a standard 2" of water flow allowance near the surface over the barrier, and we're planning on increasing the permeability from the standard liner/solid/stone/wood barriers that natural swimming ponds usually have. Instead: we're using recycled pallets and fence posts, and back-filling the regeneration zone (plants) with larger-than-gravel rocks from piles left on our farm by generations before us. This is a compromise: it's less surface area for the good bacteria to attach to, but larger rocks provide more gaps for the water to circulate. Good bacteria will also find homes on the exposed plant roots, we hope.

Anyways: keep those ideas coming. Thanks for the lime idea: where do you buy it? (BTW: because this is a spring-fed pond, everything flows down to our neighbor's farm, so we have to be VERY careful about what we put in our water.)

Pictures: Instead of giving away my photo rights, I'm posting a link to my photo record of the progress so far. First picture is our farm in 2012, when the pond was being dredged in the middle of winter. It's to the right of the larger of the two sheds in the foreground. House is on the far right; it's yellow.

The rest of the pictures are ordered sequentially; the siphon draining began on 9/2 in the evening, and we started to construct the barrier using pallets and fence posts on 9/6. Water is shown as of today (9/7) with about 1-2 more days of drainage left, assuming we don't lose our siphon.

(More pictures to be added as we go.)

Photo album of pond progress

Hydrated Lime can be purchased at Home Depot. They will have type S.

Thanks so much!

Draining down the pond and applying the hydrated lime to the minimal water that is left will have no effect on your downstream neighbors once the pond fills back up. It raises the pH too high for fish to live in the water, and when it's diluted the pH drops back down.

Here's another thread on hydrated lime to kill fish in a pond:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=386504

Thanks, Esshup

I don't have pumping capability, but we do have a spreader (hand operated) used for spreading seeds or we'd killer on small fields. In that thread, you wrote about broadcasting the lime on wet surfaces because of carp (eggs, I assume? ). Would the spreader work?

We have about six inches of murky water: probably around 2000 gallons. About 800 feet of surface area of water; 4-6 inches deep.

How much lime should I use, and will the spreader be of any use?

The hydrated lime is the consistency of baking flour.....

http://fisheries.tamu.edu/files/2013/09/...s-and-Tanks.pdf

Table 4 is the one that applies to your pond. To be on the safe side, find a pH tester that can read in the 10.0-12.0 range. Test the pH of the water after application to be sure you applied enough due to the amount of water in the bottom of the pond. It should be higher than 11.0.

For instance, a 50' x 100' area is .11 acre which would require between 165 and 220 pounds.

edit: If the water is 6" deep, you have almost 3,000 gallons in there. I'd go with 50# spread evenly over the water surface and test the pH. Buy 2-3 bags, you can always take back the unused bags. It would be easier on you if you could mix up small amounts in a 5 gal bucket (say 1/2 a bucketful of water at a time) and throw that water/hydrated lime mixture into the pond repeating the process around the edge until it's all in the pond and the remaining water in the pond has a high enough pH.

I'm at HD and all they have is this: "Pennington fast acting lime plus"

Could someone please look this up and reply with info if this is BOTH safe and effective?

This is what you want.

http://www.homedepot.com/s/type%2520s%2520lime?NCNI-5

Checking back in to report our progress.

Note to others following our project: hydrated lime is a seasonal product (spring) at HD, but we found it left over at our local hardware store!

We managed to siphon down the pond to about 4" of muddy water. I got in there with a garden rake and managed to scoop out about 40 larger carp... pretty much all of the fish over 4" long.

We put some of them into our lower pond and most of them in a 100 gallon stock tank, with hose running in the bottom for oxygenation. Then, we limed the pond. SAD to see remaining small fish struggling, but it was all over pretty quickly. We broadcast lime on all slopes, and are now continuing to work on the swimming area barrier before the fall rains begin.

Another report, and a question.

We have now finished constructing the internal barrier, and are going to finish "terra forming" the pond bottom today. Then, we will allow the pond to refill while we put together and install our windmill. Then: the final phase will be to haul rocks from all over our farm (they are in piles from previous generations' work) and put them around the perimeter such that they slope from water's edge to a 2' depth at the barrier.

I am now researching the best plants to buy for water purification. Water lilies, irises, and some kind of tame rush are all on our list. In one really reliable source, I found recommendations for Anacharis, but also a long list of states that don't allow shipment there because it's invasive. Has anyone used Anacharis for algae control/water purification? Anyone had bad experiences with it? And, please share, what are your top plants for water purification/fighting algae? (We are in zone 5, so they need to be hardy.) TIA!

I wouldn't touch it. Look up Eloda.

To fight algae, you need a plant that will utilize a lot of nutrients and grow dense. Basically any submerged pond plant that will grow in dense stands will remove a lot of nutrients.

I've noticed ponds that have significant underwater plant growth have clear water and minimal Filamentous Algae growing in them. It doesn't seem to matter what plants they are.

Anacharis is the old name for Elodea. It has several species - all problematic plants for a swimming pond IMO. The only submerged pond plants that I would introduce would be spiral or corkscrew eel grass or dwarf Sagittaria. All others are way too invasive, spread too fast and get too tall. When you choose water lilies only buy the dwarf or small varieties noted in their descriptions. There are several varieties of water lilies called changables that would be acceptable for small ponds such as: Souix, Chrysantha (aka Graziella), Berit Strawn, Little sue, Indiana, Paul Hariot, Aurora.

Keep as many organic materials out of the pond as possible, don't feed the fish and these will reduce the need for consumption of nutrients. A large biofilter or water circulating through an adjacent wetland would also help consume nutrients. Keep the grass carp out until the plants are out of control. Basically use only tilapia for any needed algae control. All other fish are usually not needed in a swimming pond unless you get lots of water boatmen or backswimmers. then use several only male bluegills for bug control. Read up and do due diligence about how others manage natural swimming ponds.

Thanks, Bill, for all those specific suggestions!

My pond surface is around 2000 square feet. Half of that is devoted to the swimming area. I have no experience with water lilies, and would like to plant a sufficient number to ring the swimming area and remove nutrients without overwhelming the pond. I have no idea of the "coverage" or "size" that water lilies grow. We will have no fish at all at first; we'll only add them back in (as you suggest above) if/when the insects become a problem. (Lucky for us, we have bats that eat larvae and adult bugs, so mosquitoes have never been an issue here for us.)

Our current plan is to start with circulation generated by two airstones driven by a windmill. I know that you're not in favor of windmills, but we'd already ordered the mill before we read that, so this is our path for now. IF we don't get adequate circulation next summer, we'll plan to bite the bullet and add electricity out near the pond and a circulating pump, unless you or anyone else here know of a pump that can run off of a Marine deep-cell battery array powered by solar?

Finding about exactly what plants have been used in natural swimming pools is not so easy to research on the 'net as you might imagine! I think those that build them for a living guard that information, maybe. If you know of any resources, please post them! I'm a due diligence kind of gal!

Esshup: would a stand of iris fill the bill for dense rooted plants that eat a lot of nutrients? If so, got some special geneses to suggest?

Also: how do we all view cattails? (Keep in mind I've got a slope of rock going to my barrier. While sediment will, doubtless, collect some on these rocks over time, I'm starting with a fairly barren surface there that might? would? curtail the invasive spread of cattails, at least for a few seasons, and I love the red winged blackbirds that will come if I plan them.) Thoughts?

Bill: Like this?

http://www.watergarden.org/Pond-Supplies/Low-Growing-Shallow-Water-Plants_2/Arrowhead

Doesn't say "dwarf." The only dwarf plants that are coming up are sold for freshwater aquariums. Would those work?

Of note: Water lillies can absorb a lot of nutrients, but they need pre-existing nutrients to thrive. Otherwise they will languish, and you don't want to introduce nutrients just to get the lillies to grow. You may need a year or two to let the pond "settle".

You could put them in baskets or pots that keep good feed soil/fertilizer contained in them, which is how most water gardeners deal with it. Eventually when the nutrients increase, so will the lillies.

That particular arrowhead is a regular variety - okay but sort of generic as arrowheads go. If you want a fancy arrowhead purchase a few double flowering arrowheads, put them in small tubs to get them established, transplant when they fill the tub with new plants. Perry's Water Gardens is one source.

Spiral eel grass.
http://www.aquariumplants.com/product_p/va069.htm
Others:
http://www.aquariumplants.com/product_p/va069.htm
Taxonomic name: Vallisneria nana
The names include:
Vallisneria americana var. biwaensis (used by John Monore central Indiana on the forum).
See this post by John:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=261781
Other names for the spiral forms used on the internet sites
Vallisneria spiralis
Vallisneria tortifilia
Vallisneria tortissima
Vallisneria torta
Vallisneria asiatica
Vallisneria contortionist

From Wikipedia:
(http://en.wikipedia.org/wiki/Vallisneria_spiralis)
I don't think the person that wrote the following on Wikipedia was a good botanist.
One form of this plant has been described: V. spiralis f. tortifolia, which has also been elevated to the species level by some taxonomists under the name V. tortissima. The form has tightly twisted leaves. Along with this form, many other trade names have been developed for small variations on the species. Their taxonomic status is uncertain.

All eel grass types (species, subspecies) are essentially warm season plants meaning they sprout and flourish when water temps are above 60F. Some of the forms are more tropical than others and these more tropical forms struggle to survive overwinter under ice cover. I have been working with one Florida strain for 10 yrs trying to get it to successfully over winter in pots 3-4 ft deep during ice cover. What I currently have survives the winter in NW Ohio. It is not real aggressive and struggles to compete with Chara and other aggressive submerged plants that like or thrive in cooler water when the eel grass plants are dormant. Adult tilapia will eat the Chara and allow Chara to be less competition for the eelgrass. Another reason for tilapia. Once the bed is dense and established it seems to do okay.

Dwarf sagittaria
https://www.youtube.com/watch?v=AM3bMoi4pWc
Focus on the twisted. Not standard(straight) nor Jungle (Giant).
https://www.youtube.com/watch?v=fa_pMF58aPE

http://www.fishandtips.com/displaydb.php?ID=57

http://www.petsolutions.com/C/Live-Foreground-Plants/I/Dwarf-Sagittaria.aspx

Plant and grow several plants in tubs in the pond and allow to multiply, and then transplant them into the pond.

I prefer the various varieties of aquatic iris compared to cattails. If you must have cattails then strongly consider dwarf cattail commonly available for sale on the web. Dwarf cattail is easier to manage compared to common cattail or the graceful cattail species.

Try making contact to other natural swimming pond people on the internet. All will love to tell you about their pond. There may even be a natural swimming pond forum. Do your homework. There seems to be lots of interest in and quite a few people around the world esp Europe with natural swimming ponds.

Blue Flag Iris or varigated sweet flag. As for cattails, I've got them trying to establish in my pond, and the nearest cattails are almost 1/2 mile away. While they may look good for a short bit, I think they might be more work then what you wish for after a number of years.

Hi, all

Things are going well on our project. The pond has been slowly but steadily refilling, and is within about 2' of final level. The windmill is up and installed, and one airstone is bubbling merrily. We need a valve to arrive from the windmill company before we can install the second airstone.

I have a question for you experienced people about pond color. Our water is clean, but green. Is that copper/minerals, most likely, or more like algae suspended in the water? (FYI: We notice green and brown colors in our bathtub (our water is all spring water) after heavy rains even after filtration, and we've had heavy rains as the pond has been filling. Since it hasn't overflowed yet, ALL the water in there includes the heavy rainfall water that we'd expect to be green.

Thoughts?

Several possibilities. Green hues are likely microscopic algae while the browns could be algae or stains / color or maybe clay/silt. One way to check for clay silt is to do a settling test. One form of this test is to collect 4-5 gallons in a white bucket and allow it to set for 4-6 days. If it forms a sediment layer on the bottom and overlying water is gin clear then it was clay/sediment. If the brown hue persists it is likely stain from plant materials, but not always. Depending on the quality and particle size of your filtration system a lot of the particles including smallest algae less than 5 micrometers could be passing through your filter system.

Thanks so much for the response. Just to clarify: the water is green AND we can't see the bottom. But, it's not muddy as it was when we had fish in there. I put some new pictures up last night. This one shows it well: https://plus.google.com/photos/101584732...32624793594302.

So now, inquiring minds want to know: what are ways to make your water gin clear that don't involve chemicals (remembering always my downstream neighbor) and do involve aggressive planting of my rejuvenation zone. Do you think that movement (a la wind power) plus competing plants like lilies (can I plant them now, before winter hits?) can make the water more clear (I know it won't be like a chlorinated swimming pool), or are there other tricks to be discovered?

Above, someone (can't see as I type this; forgive me) said that water lilies need nutrients to flourish and my pond may need to settle for a year or two. Does this dynamic relate to the presence of algae?