Planted gravel filters that use roots and bacteria to clean pond water naturally.
A bog filter is a gravel bed planted with water-loving plants. Pond water flows up through the gravel, where bacteria break down waste and plant roots take up nutrients. It is a natural, quiet and good-looking way to clean water.
We build bog filters beside or at the head of a pond, sized to the pond volume and plumbed so the whole flow passes through the gravel. Plants like iris, pickerel rush and sedges thrive in the damp bed and give the filter a lush look. The bed can sit at the edge of the pond, below a waterfall or in a separate planted garden, and we choose the layout that suits your yard, your pond size and the way the water already flows.
Water enters at the bottom of a gravel bed and rises slowly through it. Bacteria on the gravel convert ammonia and nitrite, and the roots of the plants take up what is left.
A bog filter works best when it is large enough and the flow is slow. We design the bed volume and the flow rate to match the pond.
A well-planted bog looks like a natural wetland, hiding plumbing and attracting dragonflies. It makes a lovely transition between pond and garden.
Trimming bog plants in late winter and removing old growth keeps the filter productive and tidy.
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BeforeAfterNatural cleaning in one bed.
Large surface area for bacteria.
Distribution pipes for slow water.
Iris, sedges and rushes.
Seasonal trimming and a gravel rinse.
No chemicals needed.
Every topic has its own page with what to expect and how we approach it.
Material guideAquatic PlantsWater lilies, marginals, floaters and bog plants: which grow well in Middle Tennessee and what each does for…Learn more 
Material guidePond FiltersSkimmer filters, pressurized filters, gravity filters, drum filters and bog filters compared for different ponds.Learn more 
SituationWater QualityThe basics of pond water: what to test, what the numbers mean and how clear water is kept…Learn more Enter pond volume, waterfall width and lift and see the pump flow to look for.
Tell us what you have in mind and send photos of your yard. We plan the visit so we arrive ready.
We walk the yard, discuss size, style and sound and mark the shape on the ground.
You get a clear written price, and we agree on a day and an arrival window.
Excavation with shelves and a stable slope, with protection for your lawn and a call to 811 first.
Liner, plumbing, filtration, stone and plants installed with careful attention to the hidden parts.
Water treated, flow tuned and a walk-through with you before we leave.
Usually not by itself. Koi produce a lot of waste, and a bog filter is often paired with mechanical filtration.
Yes. It can be built beside the pond and connected with plumbing.
Iris, pickerel rush, sedges and other marginal plants are the usual choices.
Trim plants and rinse the gravel gently once a year or as needed.
Late winter or early spring, before new growth starts.
Pond FiltrationMechanical and biological filtration sized to the pond and the fish so the water stays clear all season.Explore 
Aquatic PlantsWater lilies, marginals and bog plants chosen and planted in the right pots and the right spots for…Explore 
Swimming PondsA chemical-free swimming pond where a planted regeneration zone and quiet circulation keep the water clean enough to…Explore 
Algae and Water ClarityFind out why a pond is green or cloudy and fix the cause with better balance, filtration and…Explore Tell us about the job and we will call you back quickly.
Or call (615) 357-7797 to talk now.
