Should filter sidewalls be smooth to avoid short-circuiting between the walls and sand?

The correct understanding regarding filter sidewalls is that they should actually be smooth to minimize the risk of short-circuiting between the walls and the sand. Smooth walls promote even flow distribution and help ensure that water travels through the filter media effectively, rather than bypassing the filter where it could flow directly from one side to another without proper treatment.

Rough walls, on the other hand, may create turbulence that can lead to uneven flow patterns. This roughness could potentially disrupt the filtering process by allowing water to take shortcuts, thus reducing the filtration efficiency. Proper design considerations for filters emphasize the importance of smooth surfaces to maintain the integrity of the filtration process and ensure that contaminants are trapped effectively within the filter media.

It's also crucial to note that some variable factors in filter design do exist, but when focusing specifically on the characteristics of the sidewalls, smooth surfaces are preferred to provide optimal filtration performance.