This is for my low tech 125 gallon. I am taking the shortcut to getting rid of my BBA remaining problems. Plus I want to make it maintenance free or as close to it as possible, so I am going to add pressurized CO2. I have an Eheim 2028 and an FX5 on this tank. If I go with a reactor, I will go with a Rex type hooked up to the 2028. If I go with a diffusor, I would go with one being misted by the FX5.

Which would work better in my scenario, keeping in mind that the bubble rate would be fairly low (1 - 2 bps or so), since my lighting is just over 1 WPG?

Would I need more than one diffusor and misting point to disperse CO2 properly in a tank this size (it's a 6 footer)? If so, would a reactor do this more efficiently? Or is this all just personal preference? I've got a DIY rig on there right now which is working ok, but to keep the bubble rate that high, I am having to redo the solutions every week, which is a lot of work.

Once I get the pressurized CO2 working efficiently, and the bba eradicated (long story, but Tom helped me with it on plantedtank.net), then I will look into upgrading the lighting to about 1.5 wpg. I currently have 144 watts total on this tank. 84 watts with Coralife Aqualight T5's and 60 watts with Perfecto T8's.

I'd stick around 2bs or so.
You still need good CO2 if you plan on using it.
It will make the system more stable.

I'd run an in line venturi personally given the choices here.
About 30-40$.

Should do very well and no cleaning involved.

Regards,
Tom Barr

By inline venturi, do you mean the DIY unit that's in this thread?

Tom's internal venturi reactor

No, like this:

Mazzei Venturi Injectors, 1/2

Or

Venturis

or

DIY In-Line Micro-bubbler - Page 8 - The Planted Tank Forum

Regards,
Tom Barr

Thanks for the links Tom. I'll study up on this as I have a couple of months before I have a chance to do this (ordering the CO2 tanks with a group to save shipping).