Filter + Co2 Diffuser

[rimple]

We can used every drop of co2 and diffuse co2 in water by this technique. Diy co2 does not make much pressure long time for a air stone or readymade diffuser. I think that is why Rajiv says that it is best technique.
But if diy co2 liquid goes in the aquarium then it proves a very bad technique

[ishaan]

But if diy co2 liquid goes in the aquarium then it proves a very bad technique

thats why it is always recommended to use check valve