# CO2 on 24hrs or not?



## Erirku (Oct 5, 2004)

So I was wondering who else leaves on there CO2 24hrs a day, or just leaves it on when the light come on? Thanks


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## turtlehead (Nov 27, 2004)

Well it depends if its diy or pres.


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## Raul-7 (Feb 4, 2004)

Most people w/out pH controllers leave it on for 24 hours. This reduces pH swings caused by running it on a timer, but if you do this you have to keep your eye on the kH to make sure the pH doesn't crash.


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## gnatster (Mar 6, 2004)

Yes, pressurised and pH controller


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## Sir_BlackhOle (Jan 25, 2004)

yep...but with DIY.


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## trenac (Jul 16, 2004)

24/7 for me... Both DIY & pressurized.


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## paul236313 (Jul 23, 2004)

i cant leave my pressurised co2 my ph would crash due to have very soft water.I think people with very hard water can leave there co2 on 24/7


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## pineapple (May 4, 2004)

Not sure that I believe a PH crash is possible. However, I turn on CO2 2 hours before lights on and turn it off 1 hour before lights off. Lights are on for 10 hours per day.

Andrew Cribb


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## JanS (Apr 14, 2004)

Nope. Mine is on a controller, and it turns on and off several (several might be a stretch, but it's more than a few) times per day/night. Nice and steady for the fishies.


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## shalu (Oct 1, 2004)

I use a ph controller. I recently tried to use a timer instead, but in my tank, the ph keeps going down even after 5-6 hours. That means I won't be able to get a stable/high C02 level most of the day. Went back to controller  I believe 24/7 is better than on a timer for good level of CO2 during photo period.

ok, found my problem was with needle valve setting. Now I put my ph controller on the timer, works great.


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## Capt. (Nov 24, 2004)

I leave mine on 24/7. I also believe that PH swings are not a problem at all. I think only extremely high CO2 concentrations are something to be worried about. I've had mine up to a level higher than I'd like to admit and did not notice any problems with my fish.


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## Bert H (Mar 2, 2004)

24/7 for me.


> I've had mine up to a level higher than I'd like to admit and did not notice any problems with my fish.


 --Me too.


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## agzuny (Nov 17, 2004)

I use DIY and leave it on all night. To lessen the accumulation of CO2 in the water at night, I just turn up my Eheim filter which slightly agitates the water.


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## SAWALLACE (Dec 24, 2004)

Just during photoperiod here. My rationale behind this is the plants will give off CO2 during the respiration phase, that would increase pH swings during the night if CO2 was injected. Maybe i'm wrong, maybe they don't give off that much CO2, I have never monitored my pH for a complete 24hr. period. 

Feel free to correct me if i'm wrong.


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## plantbrain (Jan 23, 2004)

I do not add it 24/7.

I can add a lot for the photoperoid rather than a sustained chronic level that is going to be more harmful to fish, bacteria etc and it adds a measure of safety should an over dose occur and also saves on your gas if you use Gas tank CO2.

DIY is easy to do this way as well.

We add CO2 why?
To fertilize the plants, not to control pH, pH is just the measurement to determine the CO2.

You do not need CO2 at night at all.

The fish are not as concerned about the pH as they are about the alkalinity and GH.

FYI, pH changes are enormous in aquatic plant ecosystems, 2-3 units are common in shallow planted lakes, some times 6 to 10 in some cases.

Regards, 
Tom Barr


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## Rolo (May 12, 2004)

I totally agree with Tom.

Recently I traded wagons. Switched from 24/7 with pH controller to CO2 on only during photoperiod. My tapwater parameters recently changed, and I can get a pH swing of 0.8 every water change. Fish can't tell the difference. 

I'll be selling my pH controller soon.


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## jsenske (Mar 15, 2004)

I believe firmly in Tom's comments/approach. I don't ever leave CO2 on at night. Like the ADA approach, I turn off CO2 at night and aerate until lights on again.


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## Wö£fëñxXx1 (Feb 10, 2005)

I also pump the C02 in @ photoperiod, solenoide is plugged into light timer, off at night!!


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## WarEagleNR88 (Jan 24, 2005)

Hi, I think this is my very first post here.

I just recently set up a pressurized CO2 system and have since cranked it up to nearly 1 bubble every second for outstanding plant growth I never even got close to seeing with two 2L DIY bottles. Mind you my planted tank with the press CO2 is a peaceful community 10G running 40W of PC lighting and I also add lots and lots of a liquid mix of H2O/KNO3--I've found it easier to control growth than adding dry KNO3. Oh and lots of plants--thanks Travis.

Not really sure if it's the low pH as I leave it on 24/7, but since then I've lost two of my emerald grn cories just out of nowhere and I haven't lost a fish in this particular tank in a long time. One of the black skirt tetras is almost 2 yrs old.

pH death or something else? I've got *extremely* hard water. Mineral deposits in the toilets and bathtubs in my house every week. Thanks!


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## Laith (Sep 4, 2004)

Currently I've got the CO2 setup with a controller but maybe I'll try having the CO2 off during the night.

How's this for an idea? Plug the controller into a timer. That way you're still using the pH to control the amount of CO2 in the tank but the whole system goes off at lights out...

Any drawbacks to this?


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## MTechnik (Feb 17, 2005)

That sounds like a good idea, Laith. Anyone else have any thoughts on this?

-MT


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## shalu (Oct 1, 2004)

Laith said:


> Currently I've got the CO2 setup with a controller but maybe I'll try having the CO2 off during the night.
> 
> How's this for an idea? Plug the controller into a timer. That way you're still using the pH to control the amount of CO2 in the tank but the whole system goes off at lights out...
> 
> Any drawbacks to this?


I am doing that now, works great. Discus don't complain about ph swing(up about 0.5 before lights on). I am only doing this to prolong the CO2 bottle. I actually have the controller on a separate timer which goes on couple of hours before the lights on. The CO2 level is already on target when the lights come on.


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## OldManShiver (Mar 30, 2004)

I go the solenoid on a timer route as well. On about 15 minutes before lights on and off when the last set of lights goes off. Air pump on an opposite timer kicks in when the last of the lights go out.

As was already mentioned, the waste of CO2 at night can be avoided. Not that it's all that expensive, but still...Also, the fact that everything is using O2 during lights out - makes me feel like I'm being a better provider. 

It only takes about 30 minutes for the plants to start pearling when the first set of lights kicks on. I actually don't keep very tight tabs on my pH at all - I figure if my KH is around 3 and the plants are looking like they should, the pH is fine.


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