CO2 External Diffuser / Bubble Counter

External "diffuser" for dosing CO2 into the external filter output hose. Based on T-pipe and reduction-nipple where CO2 is supplied.
Very efficient, but only on the understanding that there must be sufficient hose length(1~1.5m) between diffuser and water outlet point in the aquarium. Water outlet should be placed under the surface of aquarium water.

NOTE: It is ABSOLUTELY necessary to use safety(check) valve on CO2 hose, near of diffuser's CO2 inlet. If you do not apply check valve, then the aquarium water chuck out through diffuser and make damage to your CO2 equipment, or simply flood your house.. oopss.

There are diffusers with following t-pipe versions available:
- universal T-pipe with screw coupling, for hose inside diameter 12-16mm with max 1,5mm hose-wall thickness
- T-pipe with press coupling, for for hose inside diameters: 12mm, 16mm, 20mm, 25mm;