Blackout and CO2 cylinder

[An t-iasg]

I may have to do a blackout to control my cyano and possibly hair algae. I have never done a blackout with the CO2 cylinder hooked up. Can I just unplug it (unplug the solenoid), or would it be better to turn the master valve (on top of the cylinder) off completely?

[Lonewolfblue]

When I did mine, I just unplugged the solenoid.

[travis simonson]

Cut the CO2 during the blackout. Your plants can only utilize it during a bright photoperiod.

Here is my blackout protocol:

1] Immediately before the blackout do a 50% water change

2] Add some airstones or powerheads to the tank if possible, but by all means maintain standard filtration

3] Cover the tank so that no light can enter

4] Turn off your heaters so that mean water temp stays below 77F

5] Do not feed, fertilize, or inject CO2 for the duration of the blackout

6] Don't peek

7] 3-5 days later uncover it and enjoy feeding your starving fish and plants that have no algea

8] As soon as you uncover the tank, do a 50-75% water change to remove the dead algae

[malkore]

I'd also pull the CO2 line out of the aquarium to prevent a siphon from pulling water out and into the regulator, which would ruin it.

of course if you have a brass check valve installed, that won't happen. if its a plastic check valve...don't trust it...pull the airline during the blackout.

[An t-iasg]

Thanks, everyone...I didn't even think about the check valve. It is plastic - I did get a Clippard one but it's too "tight" and during an underwater test, it forced CO2 out around the screw-on end pieces. I have to call the dealer again. I have seen water in my plastic check valves that were attached to a regular airline, so I know plastic can't be trusted completely.