24-hour lapse in CO2?

dapellegrini

Lifetime Charter Member
Lifetime Member
Oct 17, 2006
111
0
16
46
Phoenix, AZ
Just noticed my drop checker went blue and upon further inspection my CO2 tank is empty. My pH is back up to near ambient level at 7.7 (tap is ~7.9) and the brewer supplies place doesn't open until noon tomorrow for a refill...

Since this is the first time I have had to refill the CO2, I am wondering how others typically deal with this kind of thing? Is 24 hours ok with no CO2 on a tank that otherwise gets it 24/7? Should I dose Excel tomorrow? Other thoughts?
 

VaughnH

Lifetime Charter Member
Lifetime Member
Jan 24, 2005
3,011
97
48
88
Sacramento, CA
Amazingly, the same thing happened to me today. My drop checker was blue green, making me think the fluid in it was changed, but I checked the tank just to be sure - 0 pressure. And, of course this was just as the stores were closing. I shut off the light, and will keep it off until I get the tank refilled tomorrow. It does make me wonder what the effect would be if this had happened late Friday. Two and a half days - would keeping the lights off for that long be the answer? Intuitively I don't think a day or two without CO2 would do much harm if any.
 

dapellegrini

Lifetime Charter Member
Lifetime Member
Oct 17, 2006
111
0
16
46
Phoenix, AZ
I have also turned my lights off and will not dose until the CO2 is back online... I seem to hear a lot about inconsistent CO2 levels being the biggest cause of algae... just hoping that one day doesn't get me there...

It would be nice to have some kind of aubile alarm or warning system when the tank pressure starts to give... If not for the drop checker, I might not have looked for another day or two, when things stopped pearling, etc...
 

JoeBanks

Prolific Poster
Jun 23, 2005
70
0
6
I keep a bottle of Excel around for just such an occasion.

Or even better - get a spare 5lb tank so you can switch over - that way you don't have to rush to get the main tank refilled and the 5lb tank will last a lifetime if you're only using it for a few days each time.
 

shane

Lifetime Charter Member
Lifetime Member
Nov 29, 2006
269
1
16
Ya, it would be nice to get an audible alarm when the tank is very low. I have an extra 5lb bottle for emergency backup. As well as other parts. Never know what is going to break.
 

dapellegrini

Lifetime Charter Member
Lifetime Member
Oct 17, 2006
111
0
16
46
Phoenix, AZ
Strange thing, my pH was up to 7.7 before lights out, and this morning it was down to 7.4.... Huh... Last night I turned the lights off and pulled the plug of one of my 2 XP3s (the one that creates more water current / surface agitation)...

Anyways, I was able to make it down to a Welding Supplies shop this morning and get the tank replaced before the lights came on. I will keep a close eye on things for the next couple days...

Without that drop checker in there, I would not have even thought to check the CO2. It could have gone on for another day or two until I started to wonder why the pearling had slowed or stopped... It's even more handy than I was thinking when I set it up.
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
Some pH depression is normal and predicted/expected, there is no uptake of CO2 at night, so the plants, the bacteria, the fish are still producing some CO2, not a lot, but enough to knock the pH down.

But as soon as you add light, this amount of CO2....that took all night to produce........will be lapped up by the plants in 30 minutes and your pH will shoot back up.

So the actual rate (CO2 produced/unit time), not a discrete measure(one pH/KH measure- no time rate added) is what is important here.

So even though there is some contribution from non plant organisms in terms of CO2, the rate of production they produce is paltry.

The plants need a lot more than that.

Regards,
Tom Barr