Sand filter needs to be backwashed on a regular basis in order not to plug. The frequency of washing may vary due to variation in the load or seasonal changes in the raw water. Commonly, the backwashing is performed with an extra time to secure an effective cleaning of the filter. This extra flushing time could be avoided with a CTX 20/25 sensor that measures the flush water suspended solids.
This measurement will indicate when the amount of solids in the water decreases and at a certain pre-set level the flush is stopped and the regular running of the filter continues. Controlling the back wash by the cleaning requirement of the filter rather than time, will save cost for energy and in some cases also volume of the flush basin.