Sand Filter - "Channeling" and remedies

Sand filters are commonly used in water treatment and pool filtration systems to remove impurities and particles from water.

Praveen Kumar

11/12/20202 min read

Channelling in Sand Filters:

Sand filters are commonly used in water treatment and pool filtration systems to remove impurities and particles from water. Channelling occurs when water takes the path of least resistance through the sand, creating channels or pathways that allow water to bypass the filtration media. When channelling occurs, the water is not effectively filtered, leading to a decrease in the overall filtration efficiency.

Causes of Channelling:
  1. Improper Backwashing:Backwashing is a process where water is reversed through the filter to clean the sand. If this process is not done correctly or frequently enough, it can lead to the formation of channels in the sand.

  2. Inadequate Sand Bed:If the sand bed is not properly sized or graded, it may result in uneven flow distribution, causing channelling.

  3. High Flow Rates:Excessive flow rates through the filter can disturb the sand bed and contribute to channelling.

    Standard Remedies for Channelling:

    1. Regular Backwashing:Ensure that the backwashing process is performed regularly and correctly to prevent the buildup of debris and channel formation.

    2. Proper Sand Bed Maintenance:Maintain the correct amount and quality of sand in the filter. Replace the sand periodically according to the manufacturer's recommendations.

    3. Controlled Flow Rates:Adjust the flow rates through the filter to prevent excessive turbulence that could lead to channelling.

    4. Use of Filter Aids:In some cases, adding filter aids such as diatomaceous earth (DE) or cellulose fibers can help improve filtration efficiency and reduce channelling.

    5. Uniform Distribution:Ensure that water is evenly distributed across the entire surface of the sand bed to prevent localized high-flow areas.

    ONE STOP SOLUTION:

    Change your filtration medium to DMI65 and that takes care of remedies 1 to 5 in single shot. Please refer pointwise details below.

    1. Regular Backwashing: Backwashing time will be extended at least 2~3 times when using DMI65; as we offers "full depth filtration". This saves a lot of backwash water and down time.

    2. Proper Sand Bed Maintenance: DMI65 has a proven life of 7 ~ 10 years unlike sand medium. Reason is simple. Extended backwash is extended media life.

    3. Controlled Flow Rates: You may have control flow to bring in to Sand filters "rated velocity". But DMI65 simply adapts to the high filtration velocity; being the "rated flow"

    4. Use of Filter Aids: Not require any further filter aids. DMI65 will use the chlorine dosing available at POE. This also to a very minimal chemical consumption.

    5. Uniform Distribution: DMI65 bed itself is uniformly porous and this point is taken care; in-built.

    Happy to help with additional questions.

    PM us : praveen@medio.co.in or Whatsapp : +91 8111 975 496