I am a died-in-the-wool pH chaser, but I am learning to let go : )
running a tube outside isn't really an option for me. I put together a really cheap CO2 scrubber using a cheap media bin and CDX. I finally got tired of filling it up (it's a pain because it wasn't meant to be used with media), so I got the BRS version instead, which really isn't too expensive. It definitely makes a difference - anywhere from .2 - .4 increase. This is a real issue for me in the winter because my tank is near the furnace which services the two bottom floors.
Anyway, I was looking to give away the original reactor anyway - it's yours if you want it? It's a bit of a Rube Goldberg setup, but it does work. I'll even fill it up with CDX for you. You can at least try - PM me if you're interested (or just "bored" ; ). Many people prefer to set up it so that the reactor air is in a closed loop with the skimmer - bringing moist skimmer air into the unit is beneficial, and it constantly cycles the air from your water, to concentrate the effect.
If I remember correctly, isn't your tank right up against an exterior wall? Shouldn't be too bad to drill a hole and run it out through the mixing station?
pH will naturally go down when the tank lights go off - many people run their refugium lights opposite their DT schedule specifically to help mitigate the night time drop-off.
Anyway, do what everyone else said, and good luck!
--Ron
