These air Taps below are extremely useful if you are intending to run an air-line ring the full length of your system where is required in the actual biological filtration systems.
Each tap has its own threaded end which can be screwed quite easily into PVC pipework etc. after pre-drilling which allows you to build your own tailor made distribution to supply air.
These Air Line Check Valves simply fit in line and prevent water from the system siphoning back into the Air Pumps if the power fails or when maintaining the system and the power is switched off.
