Last year, we wrote a DIY backyard pond article that has become quite popular. We built the pond for our backyard ducks, but the concept could be used to build a backyard pond for anyone. In fact, it would be way easier to have a pond without a flock of ducks constantly in it, molting feathers and, er, using it as a giant toilet.
A recent commenter on that article, “smithmal,” asked some great follow-up questions about our backyard pond system. Rather than try to answer all of their questions in the comments, we decided to break out the answers into their own article. Thanks for your questions, smithmal!
Questions & Answers About Our Backyard DIY Pond System
1. How is your system working so far? If you were starting from scratch over again, is there anything that you would change?
After three, years, our duck pond continues to work great — especially considering that there are 6 ducks sharing the same ~1,200 gallon pond with two fish. That’s a lot of poo to process. Hindsight changes?
- As our original article noted, we did decide to add a second filter pond + smaller pump + secondary waterfall to our original system to help filter out more of the biosolids and increase aeration.
- We also added ball valves to our filter pond plumbing so that the filter pond water didn’t suck back down into the main pond during cleaning when the pumps are turned off (more on that below).
Looking back, I don’t think we’d make any significant changes to our pond system beyond those two additions, given our space and budgetary constraints. I largely have The Tyrant to thank for how well things turned out since she has a strong biology and research background, and she did the bulk of the mental lifting on this project. I’m more the brute labor who screams “meat” or “water” when I need to refuel.
2. Can you provide a brief description of how you clean your biofilter bogs?
Have you ever seen the show Dirty Jobs? If cleaning our pond biofilters was a salaried position, we would definitely warrant a visit from Mike Rowe. Since we don’t pay ourselves for this activity, we’ve thankfully managed to avoid the fanfare and TV show fame. As our original pond article details, you can use any number of things for a filter medium: sponges, steel wool pads, hog’s fur filters, etc. The filter medium serves two primary roles:
- To provide a place with lots of surface area for the de-nitrifying, water-cleaning bacteria to take up residence, and
- To capture the “muck” as it comes flowing through the system.
You’d never see as many ducks and fish continuously using the same small water source in nature as we have in our backyard pond. If we just had a couple fish, we’d probably never have to clean our filter media. But once you start adding ducks to the equation, that means regular, manual filter cleaning is something you’d need to plan for. We’ve gotten in the practice of cleaning our filters ~quarterly. I should also note that we use this water quality test kit, and even when our water looks relatively gross (murky, brownish, greenish), it still tests really well, which has surprised us. To clean our pond biofilters, we do the following:
- Unplug our pumps to turn them off;
- Immediately turn the ball valves on our plumbing system so that the filter pond water does not suck back down into the main pond;
- Take all the sponge material out, put it in a wheel barrow, then rinse the sponges out and use the “muck water” on the perennial fruit & nut trees in our garden (we don’t recommend applying this water on any plants you’ll be directly eating anytime soon);
- Bucket or pump out the muck water in our empty pond filter before returning the filter material to the empty container;
- Turn the pumps back on and add a bit of water to the pond via a drinking safe hose to bring the water back up to level.
*While we have the pumps turned off, we quickly unclip them from their pipes, remove them from the pond, pop them open, and give them a good cleaning. It takes one person about 5 minutes to clean both pumps.
3. Do you get sediment forming at the bottom of your pond and if so, do you need to clean out your pond? I’m wondering whether a swirl pool between the pond and the skippy would remove large particles and reduce the bioload on your skippy filters?
The only time we get much buildup in the bottom of our pond is in the fall when the huge oak tree in our backyard drops half of its leaves into the pond. Unfortunately, that means that I have to hop in to the pond a couple times each year to pull the leaves out by hand or by net. Thankfully, the pond is only about thigh deep (I’m 6’1″). If it weren’t for the oak tree, I don’t think there’d be significant buildup of debris in the pond. What about a swirl pool? We’re not aquaponics experts, so it might be worth someone else giving this a shot. I’m not sure how that would work though, given that our pumps are situated in the bottom of the main pool and they aren’t able to pump up large debris/particles.
4. In addition to your skippy (microbe) filter, have you thought about filtering your water through an hydroponic system? The plants you use could provide additional filtering and landscaping to your pond. Also, some of the plants you grow could be given back to your ducks as an additional source of nutrients.
Yes! We’d love to use the water from our pond to feed plants in a hydroponic system. Problem is every edible plant we put anywhere near the pond gets immediately eaten by a flock of feathered terror-birds, aka ducks. Also, we don’t have the space in our back yard or the inclination to set up an elaborate aquaponics structure, so we grow food with the water in a less technologically sophisticated way… As mentioned above, when we clean the filter ponds, we use that water in our garden.
We also have designated “duck gardens” where we grow plants that our ducks love - chickweed, chicory, lettuce, etc. We’ll use some of the pond filter water on those beds as well, to keep that virtuous cycle on repeat.
5. I see that you keep your pool open year round. What happens to your microbe population during the winter time? Do you need to re-populate it in the spring again?
My guess is that water microbes work similarly to soil microbes. Each season sees different species active, and the warm months are when the widest range of species are most active. Just because warm weather bacteria are dormant in the winter doesn’t mean they won’t perk right back up when water temps return to a favorable range though. Nevertheless, we have two factors working against us in our system as we try to “team” with our microbes:
- Significant pressure on our pond from duck and fish waste relative to the size of the pond and the number of beneficial microbes that can reside there;
- We clean our filter medium, so we’re likely getting rid of a significant portion of our microbes.
That means we do add beneficial microbes back to our pond a few times per year, usually after a cleaning.
- Cool weather transition bacteria – to help break down pond debris in the late fall as we head into winter, we use this pond bacteria;
- Winter pond bacteria – Throughout the winter, we’ll use this cold water pond bacteria;
- Warm weather transition - We use this pond bacteria in early spring (mid to late April in our Zone 7B) as soon as the pond starts to warm up;
- Summer pond bacteria – during the warm months we use this warm water pond bacteria.
Do we have to use all of these pond bacterias to keep the system in balance? We don’t know but we don’t really want to risk it since our ducks’ health is at stake. We’d rather pay a little upfront to keep things in good order rather than pay for a sick duck later. It’s a bit like using a compost tea as a foliar spray in your garden to prevent pathogenic microorganisms from gaining a foothold – prevention/maintenance is always much easier and less costly than fixing a sick or broken biological system.
6. Can you explain where your pumps are placed. Are they both in the skippy filtering pools? How long do you think your pumps will last since they are dealing with pumping water with heavy bioloads in them?
You should be able to see the pump placement in the photos from the original article (sorry the images appear small – you can click to enlarge).
- Our large primary pond pump, the Laguna Max-Flo 2900, is situated at the lowest point in the center of the large end of the pool. We have it propped up off the bottom of the pool on top of a large flat rock to reduce the likelihood of it getting clogged with leaves/debris.
- Our smaller secondary pond pump, the Laguna Max-Flo 900 which we added when we put in our second filter pond, is on the opposite side of the main pond (the small side). Each pump is plumbed to pump water out from the bottom of the pond, up and into the BOTTOM of its designated filter pond. Then the water filters up through the filter media in the bog and out of the top of the bog pond down a waterfall and back into the main pool.
7. Would you consider shooting a video of your pond system and narrating each section of your pool. A video would help out a lot with visualizing how your pool and biofilters work together.
Sure! We’re not great at video editing and have severe time constraints right now since we’re also starting a farm, but we’ll try to get some pond videos posted over the next quarter. Hope this helps and let us know if you have more questions. Same goes for anyone else with new questions!