Originally Posted by plantedtankfan
I am using a powerade 16 oz bottole as my diffuser. How far should I fill it up with water.
I assume you mean separator and not diffuser. I'd fill the separator maybe 3" from the top. You need a little room for potential over flow from the reactor, and you obviously need an air pocket at the top or fluid will get pushed up your airline.
Also, not all DIY's show this, but you'll want a check valve between the reactor and the separator, and as close to your reactor as possible so you can disconnect it for a swap out without depressurizing and loosing the CO2 that's in your separator.