1. Do not use coral sand as a filter bed substrate as this will gradually dissolve and affect the calcium level.

2. For the best distribution of water throughout the filter bed, a finely slitted filter plate is usually more effective.

3. The application of hybrid ecological filter bed and photocatalytic technology to treatment of landscape water in a residential area was introduced with an engineering example.

4. Based on numerous test data, the influences of filter bed composition on the effect of direct filtration of raw water using an upflow polystyrene filter were discussed.

5. The functions of the hydrophyte filter bed(HFB) for improving source water quality were surveyed in terms of microcystin and trace organic pollutants.

6. To study filter bed would be silting is the key point concerning the expectancy service life of the filter project.

7. By controlling operation parameter after filter bed having been inoculated , the technology has removed iron and manganese successfully from groundwater with high concentration of iron and manganese.

8. The filter bed is rinsed with the feed liquor for 3.5 min.

9. The counter- flushing may make the filter bed long- term effective use, reduce the service and the comprehensive cost.

10. The powerheads should draw the whole volume of the tank through the filter bed at least three times each hour.

11. As a new type of biological odors control technology, biological filter bed has been developed at a great speed in its application.

12. In the KDF filter, effect of contact reaction time, filter bed height, and filtering velocity on lead and mercury removal was studied.

13. Backwashing is one of the Methods: To maintain a filter bed clean.

14. It puts forward some main factors that influences the silt, which are structure characteristics of the filter bed, water quality of river, the condition of water force and the technology ...

15. Regenerate the softener before you use it. Use clean, chlorinated water to backwash the filter bed.

16. The adsorption characteristics of phosphorus onto granular fly ash and its phosphorus adsorption ability as the material in filter bed for landscape water treatment were investigated.

17. The results showed that adding 5% dose of fly ash when feeding wastewater into the filter bed, wastewater treatment capability of facility can be improved, and the operating cost can reduce also.

18. A new solid-liquid separation technology is proposed, which uses a suspended media filter bed to separate activated sludge and water.

19. Backwashing is one of the methods to maintain a filter bed clean.

20. The filter film plays an important role in water purification in seepaging well with natural filter bed.

21. The filter film plays an important role in water purification in well with natural filter bed.

22. As a new type of biological odor control technology,[ ] biological filter bed has been developed at a great speed in its application.

23. The result shows that selection of suitable contact reaction time, filter bed height, and filtering velocity may result in efficient removal of lead and mercury.