Oh... Okay. That makes a lot of sense now. But would the addition to a gas separator take longer for the CO2 to travel to the tank, or am I wrong?
Initially when you first set everything up, having the gs bottle will mean an extra hour or two (guessing) before the whole system is pressurized, and CO2 is actually going into the tank. Otherwise it is a total non-factor. I would most definitely include one.
One more question, I noticed in your Journal you used a powerhead to distribute the CO2 to the rest of your tank. Would this be a solid way to do so? I don't mind investing in the powerhead, but I honestly don't know what other pro's it brings to a freshwater tank besides distributing CO2.
Benefits of a powerhead are circulation, and added filtration if you use a pre-filter sponge.
As a diffuser, the powerhead is working well. I think it is best to "pre-diffuse" the co2 first though. That way the propeller is working against a bunch of tiny bubbles instead of one big one. In the journal I had a piece of regular cotton ball stuffed tightly into the end of the line. Now I have a 1" piece of chopstick. The bubbles are finer and it lasts a lot longer.
Lots of people with DIY only use a cotton ball, chopstick, or a cigarette filter, and that's it. Then place the diffuser under some current, or a filter intake for optimum dispersion. This works OK, but you lose a lot of CO2 off-gassing at the surface. Imo DIY is limited enough already, so you want the absolute best diffusion possible.
Not sure what kind of filter you have, but Aquaclear HOBs make a great diffuser by themselves, due to their unique design. I have one on a 20 gallon with the co2 line going directly into the intake (pre-diffused w/chopstick). Zero bubbles, which means near 100% dissolution. Here's a pic
There's also a hole in one of the pieces above the motor that some people run the line into. You can google around and find how to do that, and about a million other ways to diffuse diy co2.
A reactor is best if you have a cannister filter, or they can be run with a powerhead too if you dont mind the additional "gear" inside your tank. Again, google around you can see dozens of examples.
Regardless how you do it, the goal is to have the finest bubbles possible, in the water as long as possible. Big bubbles go straight to the surface and pop before dissolving.
** Edit - I just noticed in that other post that you actually do have an Aquaclear HOB, so I would definitely use that. Stick a piece of cotton ball or chopstick in the line and you'll be good to go.