Natural Filtration 301 Chapter 8
Sizing Bogs
There’s plenty of good information out there, thanks to generous and knowledgeable leaders in the business like Dick Schuck and Kelly Billings at Maryland Aquatic Nurseries, the Nelson’s of Nelson Water Gardens in Katy Texas and the folks at Floating Islands International. The jury is in; any bogs are a good thing for nutrient removal and algae control. Just how much to plant depends on the nutrient load. Planting even 10% of the surface area of a lightly stocked water garden will help control string and floating algae blooms. In heavily contaminated environments like sewage lagoons 100% of the surface might be covered with floating islands for maximum nutrient intake and effective odor control.
Generalizing formulas for ornamental ponds is difficult because nutrient levels and plant “appetites” vary widely, but there’s a general consensus that passive perimeter bogs totaling 20% of the surface area of the pond will keep garden ponds where the fish are not fed or are fed infrequently algae-free. Heavily stocked Nishiki-goi ponds where fish are fed daily could need up to 60% of the surface of the pond planted if that’s the only filtration in the pond. As you might expect, floating islands with their hanging gardens of free-floating roots seem to handle about twice as many nutrients per square foot as passive perimeter bogs, so surface areas in the range of 10 to 30% seem sufficient for light to heavy organic loads.
The species of plants used also makes a difference. Certain plants take up nutrients more rapidly than others, and different species are more effective at taking up particular nutrients or contaminants, but that’s the topic of a more advanced future seminar.
There’s plenty of good information out there, thanks to generous and knowledgeable leaders in the business like Dick Schuck and Kelly Billings at Maryland Aquatic Nurseries, the Nelson’s of Nelson Water Gardens in Katy Texas and the folks at Floating Islands International. The jury is in; any bogs are a good thing for nutrient removal and algae control. Just how much to plant depends on the nutrient load. Planting even 10% of the surface area of a lightly stocked water garden will help control string and floating algae blooms. In heavily contaminated environments like sewage lagoons 100% of the surface might be covered with floating islands for maximum nutrient intake and effective odor control.
Generalizing formulas for ornamental ponds is difficult because nutrient levels and plant “appetites” vary widely, but there’s a general consensus that passive perimeter bogs totaling 20% of the surface area of the pond will keep garden ponds where the fish are not fed or are fed infrequently algae-free. Heavily stocked Nishiki-goi ponds where fish are fed daily could need up to 60% of the surface of the pond planted if that’s the only filtration in the pond. As you might expect, floating islands with their hanging gardens of free-floating roots seem to handle about twice as many nutrients per square foot as passive perimeter bogs, so surface areas in the range of 10 to 30% seem sufficient for light to heavy organic loads.
The species of plants used also makes a difference. Certain plants take up nutrients more rapidly than others, and different species are more effective at taking up particular nutrients or contaminants, but that’s the topic of a more advanced future seminar.
