How to control DIY CO2 levels

[Cheez]

I'm starting up a new diy co2 system in my low-light 26gal (1.8 wpg) because the plants arent doing very well and my ph is 7.8-8.0. Because its such low light I only really want 10 ppms running. How much do the usual diy co2 systems put out? By usual I mean a 2-liter bottle yeast system. I will be using the Hagen mini powerhead method for diffusion. If they do produce too much CO2 should I "A" : Use the same 2L bottle but fill it up with less yeast/sugar/water or "B" should I simply use a 1L bottle and fill it up the standard amount (right where it begins to curve) or "C" : Am I puting way too much thought into this? Thanks for the help.

[epicfish]

You're putting too much thought into this.

Just plumb the output of the CO2 system into your powerhead.

[Cheez]

haha thanks epicfish. you're right...but i think I'm just gonna blow bubbles with a straw every minute or so, should do the trick

[epicfish]

Haha. If you really want to, you can run an airstone via a timer to turn on at night.

Otherwise, just set it up and enjoy!

[midnightk]

sorry in my brain says why do you need co2........how many plants and fish in that 26g with 46.8w. do u use ferts???

[epicfish]

Originally Posted by midnightk

sorry in my brain says why do you need co2........how many plants and fish in that 26g with 46.8w. do u use ferts???

CO2 helps at all lighting levels.

[LarryB]

Does running an airstone at night really lower Ph?

[eyebeatbadgers]

Originally Posted by LarryB

Does running an airstone at night really lower Ph?

no.

Where did you hear that?

[epicfish]

Originally Posted by LarryB

Does running an airstone at night really lower Ph?

If anything, it raises pH by outgassing CO2.

[jjp2]

you should not get too much more than 10 ppm running a DIY (maybe a 2.5 gallon with 2-3 2-liter bottles right after filling all bottles could be an exception). If you do, there are many on here that would love to know the secret.

You will not have much pressure build up so the powerhead is likely the best option to diffuse.

You should not have to worry about out-gassing at night as you will not have much ppm in the water to start with.

[eyebeatbadgers]

Originally Posted by jjp2

you should not get too much more than 10 ppm running a DIY (maybe a 2.5 gallon with 2-3 2-liter bottles right after filling all bottles could be an exception). If you do, there are many on here that would love to know the secret.

You will not have much pressure build up so the powerhead is likely the best option to diffuse.

You should not have to worry about out-gassing at night as you will not have much ppm in the water to start with.

I ran two 2liter bottles of DIY CO2 in my 29 gallon tank for several months, and with the right mixture, could turn a drop checker green all day. 10 ppm is an arbitrary useless estimation at best. There is no reason to be afraid to achieve 30 ppm, unless you are killing fish (you won't). The amount of CO2 produced depends on how much yeast is active in the bottles, and two 2 liter bottles should be sufficient, I would recommend changing the mixture of each bottle alternating every week (so each mixture lasts two weeks only). This will provide steady consistent levels of carbon, and provide good clean growth, as long as you don't overdo it on light. Good luck, and research the info on what you are told in forums