[dubvstudent]

Took a long weekend and left town to visit some family... Turned the spray bar orientation from a horizontal configuration to verticle (just to see/sick of HC getting tore up). Came back to find my drop checker radioactive yellow and only snail life hanging on in the tank.

Just goes to show surface agitation makes all the difference in terms of CO2 levels. I feel bad for my Serape Tetras. Looks like they paid the ultimate price for my stupidity.

 

[HolyAngel]

Aww horrible! That had to be the worst feeling to come home and see that
Definitely sorry for your losses!

... On the bright side though you now have ample time to rescape or do whatever you might've wanted to do to the tank that you couldn't do before since it was stocked... :/

 

[AirstoND]

What I do

When I'm away, I use a properly adjusted airstone below Elite intake. I have a DIY yeast setup line going into Elite's venturi intake. Air + CO2 mix did not result in CO2 drop checker fall below green color.

I also keep a glass lid on top of tank

Assuming you're using a regulator/pressurized setup...
Next time you're away for a long time I recommend a 2L DIY Yeast setup if your tank is <20gal, 4L if your tank is >20gal