2. Primary filter
3. Secondary filter
4. Ultra violet disinfection unit
5. Main airlift pump
6. Aeration and airlines
7. Overflow from filter box to main tank
8. Overflow from inner tank to main tank
9. Operating water levels
10. 150kg ( or 510kg ) rated access cover
11. Electronic start/stop control
12. Air compressor
13. Control box
14. 400 litre inner tank
15. Secondary airlift (to UV disinfection unit)
16. Power connection