# Achieving stable CO2 levels with yeast



## kwonger81 (Mar 29, 2006)

Hey guys,

I've been checking my CO2 levels more regularly lately, and I've noticed that in the mornings, my pH is 6.8 (KH=7, therefore using Chuck's calculator CO2=33) but in the evenings it is 7.2 (CO2=13). I'm using 2 of the Nutrafin yeast CO2 systems (one started on April 5, the other on April 14), and I always add baking soda to buffer my brew. I've got PC lights (3 wpg). I've got a third Nutrafin kit that I could set up, but I'm worried that it'll be too much, since the morning CO2 levels are already 33ppm.

Does anyone have any suggestions for achieving more stable levels of CO2 in my tank? I know this wouldn't be a problem if I go pressurized, but I want to see if there are any solutions short of that.

Thanks,
Jeff.


----------



## ranmasatome (Mar 14, 2006)

Jeff.. why do you buffer the solution??
If the tank is planted it is only definately going to be high in the morning as plants dont take in the co2 when not photosynthesizing...further more your yeast bottles dont stop production throughout the night... Therefore, You co2 levels fluctuate. high in the day and low at night..b4 lights off..
Have you tried not buffering the solution? if its too high at night just add an air stone at night.. then in the morning remove it.
Personally this would be what i'd try.... since your co2 production is 24/7 using yeast bottles.
i've been using presurised for close to 10yrs already... and may ahve forgotten my yeast methods...so these are just thoughts..


----------



## holocron (Mar 12, 2006)

ran you are exactly right. When I 'yeasted' my PH would swing from 6.3-6.4 in the morning to high 6.8ish at night. Just one of the trade offs running your CO2 24/7, PH swings.

now with pressurized I am a solid 6.7 PH all the time that's with no controller, just a good ole PH colour tester in the tank.


----------



## kwonger81 (Mar 29, 2006)

Ran, I've heard that one should buffer the yeast brew so that it doesn't become too acidic and kill off the yeast. Thanks for your suggestion of running an airstone at night. I think I'll try my Hagen powerhead - it's got that Venturi aerating feature, so I can open up the valve at night (to blow air into my tank and therefor decrease the CO2 levels at night) and then close the valve in the morning (to allow the CO2 levels to build up again). In that case, I think I will set up that third Nutrafin set, since my evening CO2 levels (before lights off) is only 13ppm. Out of curiosity, where are you, Ran?

I'm giving pressurized some SERIOUS thought. Holocron - you set yours up recently, right? How much did it all cost you? I will check out those threads to read up on it some more.

Jeff.


----------



## holocron (Mar 12, 2006)

it's all here:

http://gtaaquaria.com/forum/showthread.php?t=297


----------



## kwonger81 (Mar 29, 2006)

Thanks Matt - I've been reading all your threads since my last post. Awesome info!! I'm getting VERY tempted now!!! Anyone else thinking about taking the leap?


----------



## holocron (Mar 12, 2006)

no worries,

I have been wanting to go pressurized for a long time, just had to save my pennys to do it. So far so good, its really easy and very very consistent. My PH doesn't swing, it just slowly goes lower and lower (still working out my bubble rate).

I would recommend it if you have $250 burning a whole in your pocket. If you want to get it *immediately*, I did see a regulator on the shelf at the menagerie last night.  Not sure how much Harold sells it for. (am I feeding that fire or what!)


----------



## kwonger81 (Mar 29, 2006)

Oh, so so so tempting!!!

I'm going to have to think about it some more. 

I'm just wondering - did you do anything about the fluctuating pH when you were yeasting?


----------



## holocron (Mar 12, 2006)

nothing much you can do besides running an airstone at night. You can't turn DIY off (if you did put a valve on it, you might have a sticky explosion on your hands). The airstone at night helped, but sometimes depleted my CO2 down to next to nothing... so it was a balancing act trying to get the air pump to run at a rate that kept the co2/ph at a safe level. Needless to say it was a pain in the ass.

But it's cheap!


----------

