Having a small garden, lots of patio area, and wanting something low maintenance I decided on a garden patio pond with bog filter.
The bog filter that sits above the pond is very low maintenance as it’s such a huge area filled with lots of media.
The build went pretty much as planned. We used decking for the wood with some 2×2 inch wood in the corners to screw them together to create a box. The same material and structure was used to create the bog that sits on top. Just on a smaller scale.
The pond is 1 meter wide, and 700cm front to back. It’s about 600cm high. With the bog included the total amount of water this pond holds is around 500 litres.
I used about 200 decking screws, some pond liner and the sponge that goes in between the two, to stop anything sharp piercing the liner. Although it’s only wood I thought it best to be safe.
The bog filter just sits on top as the weight of the wood, all the stones and water flowing through makes the unit very heavy and unmovable.
The only ongoing cost is the small pump which consumes 20 watts. I drilled in an outside waterproof socket, and the pump just plugs into the wall. Very tidy.
How the bog filter works
Your standard pond filter is usually a box sat outside the pond where water pumps into it and then back out of it. After a while though you have to open it up and clean it out. These filters can be very expensive.
The bog filter works by a very cheap, small pump (1200LPH) in the bottom of the pond pumping water up into the bottom of the bog structure at one side. The water travels through a 1 1/5 inch tube that runs along the bottom to the other side of the bog structure. The pipe has small holes drilled out along its bottom.
The water rises up from the holes in the pipe, and equally through the stones (media) and out through the 3/4 inch hole in the centre of the filter box. I also installed another 1 1/5 inch tube in the opposite corner to the intake to act as an overflow.
The overflow pipe sits higher than the 3/4 inch outtake and travels straight down through the bottom of the bog and into the pond. If for some reason the 3/4 inch outtake gets blocked or cant handle the flow, the water will simply overflow down the overflow pipe, rather than the edges of the bog and onto the floor.
I used some cycled media from my aquarium to kickstart the cycle. However to give the cycle a further boost I added a product called Pure Pond from Evolution Aqua. It’s a tub of gooey balls that contain a ton of bacteria. They’re supposed to consume the ammonia and nitrite and turn your water crystal clear, like a mature filter system would. I figured they could help and purchased a small 500ml container. I then buried them into the stones.
Plants are fantastic, I’m into aquatic plants just as much as i’m into the fish. At first I did some research into which plants I wanted, but as the options are so vast I thought id visit a pond/aquarium shop and just pick a few out that I liked.
One plant I knew I wanted however was the Creeping Jenny. This is a bog plant that I could sit in the top of my bog filter. The roots will spread down into the media and the waste from the fish. The plant will spread all across the top and maybe even down into the pond, eventually overhanging. This plant also sprouts yellow flowers. I purchased a few bunches of this from eBay.
Another great plant is the Water Lilly, although they can be expensive. My mom had one sitting in a barrel full of water from my grandads old pond. Not much was happening with it. I dropped it in the bottom of the pond, and after a few days the Lilies grew up towards the surface. Eventually a very large colourful flower will sprout.
Not many fish can be survive the outside English climate. I was thinking of some English river fish but then decided to go for the typical hardy goldfish. The pond verity.
These fish are bright orange so they’re highly visible against the black liner. They’re cheap, grow nice and big, and won’t die off in the winter.
Koi are always a pond favourite but need huge ponds, are very expensive and more fragile than your typical goldfish.
My fancy lights
For lighting I bought a pair of relatively cheap LED solar panel lights. I screwed the brackets provided onto the fence just above the pond. After being charged by sunlight they provide a very dim light that lights up the pond at night time. However when the PIR sensors are triggered by movement the light shines very bright. Like two miniature flood lights.
These lights are great for viewing the pond at night time. They’re so bright I can watch all the fish even in pitch black. They will then go dim again once movement is no longer detected, so the fish can still rest.
The result was even better than I’d hoped. As soon as the liner was screwed in place, I plumed it all in, started the pump and it just worked. Nothing leaked or overflowed out onto the ground.
The pump feeds the water from one end of the pond, up through the stones and the water rises and overflows out into the middle. This creates huge surface agitation allowing plenty of oxygen to be dissolved into the water. Surface agitation is very important otherwise the water will go stagnant and they’ll be a lack of oxygen.
The decking which is relatively cheap for wood, created a solid strong structure when it was all screwed together. Decking looks good, and does the job.
Once the plants grow In this pond will look even better. A lot of these plants will eventually flower. The large bog will support the goldfish sufficiently and in turn the fish will feed the plants with their waste.
I think if I built this again, the same, I could do it very quickly and with ease. It’s a simple build and no corners are cut doing it this way.
My main inspiration was from The Pond Digger on YouTube. A full guide to how this build works on a slightly larger and American scale: Inspiration and guide.