Upgrade Your Pond with a Bog Filter System
As we prepare for a third summer managing our 300 gallon stock tank garden pond, we have a new upgrade to share. During the last two summers, we conducted pond water changes by taking buckets of water out of the pond and pouring them out on the garden beds. This was a fairly labor-intensive process, which I didn’t mind, but I knew there was probably a smarter solution to make use of the fish waste and keep the pond water nutrient levels down.
Back in the fall, I ran into a customer at Logan’s who was also shopping some water plants, and she mentioned that she had a “bog filter” in her pond. She used a pump cycle pond water into a small bog in an elevated section of her pond to clean the water via plants. Fast forward a few more months, and I participated in several conversations with other gardeners who ran aquaponics systems to grow vegetables and convinced me that a bog filter to grow more veggies was the way to go.
Online resources recommend that the bog filter be sized anywhere from 10 – 30% square footage or volume of the main volume. With a 300 gallon main pond, the 110 gallon bog exceeds the higher end of that range but it gives us extra space for vegetable baskets. The combined volume of 410 gallons (generous estimate considering all the rocks) led us to select a 420 gal/hr pump.
The setup
The Tuff Stuff KMT 100 Heavy-Duty Oval Stock Tank (Tractor Supply)
3/4″ supply line with 6 parallel 1/2″ distribution lines and 6, 3/8″ holes per parallel line
3″ lava rocks covering the supply lines
4″ corrugated perforated pipe sock
8 bags drainage rock
The overflow pipe allows about 1.5″ standing water above the crushed stone
smartpond 420-GPH Submersible Pond Pump, garden hoses and connectors (Lowes)
After we had the bog filter up and running, I planted out the 6″ pond baskets with clay pebbles and vegetable starts.
PONDMASTER POND PLANTAINTER 3760 Square Plant Basket (affiliate link)
Several weeks later, I tested the pond nutrient levels, and everything looked to be on mark. With 13 juvenile fish, I’m not sure they produce optimum nutrient loads, and I’m not sure what those optimum levels even are, but this is a year to observe and learn. I just wish they would eat back more of the algae!
Next weekend I’m taking the remaining plant starts to a neighborhood swap, so I’ve been using the bog filter as a holding zone for tomato and pepper starts when they get a little too dry. If a plant’s soil looks parched, I wedge it down between the baskets to soak up water and nutrients.
When I lifted one “big beef” out of the water today, there was a large amount of new root growth after only two days in the water. Joe and I decided we could leave it in the bog but set a tomato cage just outside the bog (the rocks prevented the cage from being stable in the filter, and then we will train the tomato into the cage as it grows. Of course, this variety is enormous and this will likely be an unruly disaster, but I’m already pondering the benefits of being able to grow tomatoes in the filter and never have to worry again about irregular watering or soil diseases.
This first year we are attempting strawberries, leaks, peppers, beets, watercress, cantaloupe, watermelon and mint. The strawberries in the bog filter are already thriving!
Shop for Supplies!
The following contains affiliate links.
Pond Pumps
Look for a pump that will cycle your full pond volume every hour.
Fish Barrier
The pumps won’t suck the fish in if you have them in a box or a protective net. Look for something simple like this: Large Pump Barrier Bag, 17.3″x 17.3″ Pond Pump Filter Bag, Black Media Bag Large Pump Mesh Bag for Pond Biological Filters(Black) – By Coolrunner.
Stock Tanks
Rubbermaid Commercial FG424288BLA Structural Foam Stock Tank, 100 Gallon Capacity, 53″ Length X 25″ Height, Black by Rubbermaid Commercial Products
Rubbermaid Commercial Structural Foam Livestock Tank, 150 gal, Oval, Black – Includes one Each. by Rubbermaid Commercial
Little Giant Poly Oval Stock Tank (Black) Heavy Duty Feeding & Watering Trough for Livestock (15 Gallon) (Item No. ST15) by Miller Manufacturing
Tuff Stuff Products KMT101 Oval Tank, 40-Gallon,Black by HORIZON DISTRIBUTION
Clay Pebbles
Organic Expanded Clay Pebbles LECA Grow Media for Indoor Plants, Orchids, NFT DWC Hydroponics, Cactus, Succulents, Aquaponics, Aeroponics Garden Soil Additive Conditioner Amendment Ceramsite Aggregate by Cz Garden Supply
Mother Earth Products HGC714114 Hydroton Original Expanded Clay Pebbles, 25 Liter, Terra Cotta by Sunlight Supply Inc.
Lava Rocks
Drain Pipe
Perforated Corrugated Expandable Flexible Landscape Drain Pipe, 4-in. by 25-ft. by Cleveland Tubing
Aquatic Plant Baskets
TotalPond Aquatic Plant Basket, 10-inch by Geo Global Partners
Danner Manufacturing, Inc. PONDMASTER Pond PLANAINTER 3760 Square Plant Basket by PONDMASTER POND PLANTAINTER
5″ Round Water Garden Pond Aquatic Plastic Mesh Slotted Plant Basket X 3 Pack, Pond H2o Plastic Water Garden Planting Basket Aquaponics, Hydroponics Slotted Mesh by United Aquatics, LLC.
G&B 7pcs Aquaponics Floating Pond Planter Basket Kit – Hydroponic Island Gardens Aquarium by jc aqua
2 Comments
Nilu Hoyt
Hi,
I am planning to create a bog in a 26 gal container for my pond. The bog will sit outside the pond(2,500 gal). I am trying to figure out how to get the water from the pond to the bog. Do I have to use a pump to send the water from the pond to the bog barrel? If I use a pump, will it suck the fish out from the pond to the bog? That’s what I am afraid of. Please give me some ideas on how to do this project. Thank you.
Paige Puckett
Yes, I use a little pond pump I picked up at Lowes or Home Depot. If you have fish in the pond, you want to fully cycle that water and should get a pump rated for the volume of the pond. The pumps won’t suck the fish in if you have them in a box or a protective net. Something like this: Large Pump Barrier Bag, 17.3″x 17.3″ Pond Pump Filter Bag, Black Media Bag Large Pump Mesh Bag for Pond Biological Filters(Black) – By Coolrunner. Here’s a pump: Hydrofarm AAPW550 33-Watt 550 GPH Indoor/Outdoor Hydroponic Aquarium Pond 6ft Power Cord for 55 Gallon Reservoirs Submersible Water Pump, 550-GPH, Black