6 Inch Filter Brushes in Rectangular Chambers – Double Interlocked Spacing
How Many 6 Inch Brushes Do I Need for a Rectangular Chamber?
6 inch (15cm) diameter Black Knight filter brushes are an ideal choice for larger rectangular filter chambers. Their greater diameter means you need fewer brushes to fill a given space, making them a practical and cost-effective option for medium to large pond installations.
What is Double Interlocked Spacing?
Double interlocked spacing means each row of brushes is offset from the rows either side, so the brushes nestle into the gaps between one another. This eliminates wasted space, reduces the chance of water bypassing the filter medium and creates a larger surface area for biological filtration.
Worked Example
A rectangular chamber measuring 25 x 15 inches (75 x 50cm) would require 15 brushes of 6 inch (15cm) diameter using double interlocked spacing to fill it effectively. The diagram below illustrates this arrangement.
To work out how many brushes you need for your own chamber, measure the internal dimensions and use this as a guide. Our team is always happy to help with calculations — just get in touch with your chamber size.
Why Choose 6 Inch Brushes?
6 inch brushes strike a practical balance between coverage and ease of handling. They are particularly well suited to larger rectangular chambers where using 4 inch brushes would require a very high number of units. They are just as easy to clean and maintain as our other sizes and, like all Black Knight brushes, they will last indefinitely with proper care.
If your chamber is circular rather than rectangular, see our guide to 6 inch brushes in circular chambers. For the largest rectangular chambers, 8 inch brushes may be a more practical option.
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