# co2



## Dielectric (Oct 7, 2008)

so i set a glass of tank water out overnight and let it degas. i tested the PH today it was 7.7. so according to some threads i read, a ph difference of 1.0 = roughly 30ppm of co2. so i should be shooting for a ph of 6.7 in my tank? i have been pushing it lately down to 6.1 and its taking its toll on my fish, not to mention im blowing through tons of co2.

am i correct in this assumption?


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## Seattle_Aquarist (Mar 7, 2008)

Hi Dielectric,

The amount (and types) of dissolved gasses in the water pipes from our water company varies with the temperature of the water and the time of the year. Because of that fact I use a drop checker with 4.0 KH water and indicator fluid so I don't have to constantly try to monitor what my water company is doing.


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## Dielectric (Oct 7, 2008)

Seattle_Aquarist said:


> Hi Dielectric,
> 
> The amount (and types) of dissolved gasses in the water pipes from our water company varies with the temperature of the water and the time of the year. Because of that fact I use a drop checker with 4.0 KH water and indicator fluid so I don't have to constantly try to monitor what my water company is doing.


i use recostituted RO


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## Seattle_Aquarist (Mar 7, 2008)

Hi Dielectric,

I realize that reverse osmosis removes minerals from the water but I am not aware of any effect on dissolved gasses.


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## Dielectric (Oct 7, 2008)

Seattle_Aquarist said:


> Hi Dielectric,
> 
> I realize that reverse osmosis removes minerals from the water but I am not aware of any effect on dissolved gasses.


the water sits in storage for a week to a few days before its used for water changes. does this make a difference?


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## Seattle_Aquarist (Mar 7, 2008)

Hi Dielectic,

According to this chart, with a KH of 0.5 a PH of 7.7 has a CO2 concentration of about 0.3 and a PH of 6.7 has a CO2 level of about 3.0. With a PH of 6.1 and KH of 0.5 you would have CO2 level of about 11.75.

Do your plants "pearl" after the lights are on for a while?


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## cbwmn (Dec 18, 2007)

Several times I’ve raised the question about the 
accuracy of drop checkers on different boards. 
The DC colors indicate:
If the DC is blue = not enough CO2
If the DC is green = “ABOUT 30 ppm CO2 saturation”
To me, three different indications of CO2 saturation 
is not an accurate way of testeing for CO2.
On another board, Tom Barr answered that DC’s are a 
waste of money.and he says he does not use them.

Quote “________________________________________
I do not use them, waste of $ and time IMO.
The best I can say is using a pH meter as a "relative" gauge for CO2.

Otherwise, eyeballs, trail and error, careful, never to adjust the CO2 higher without being around the watch etc, good surface movement, but not enough to break the surface, watch plants etc, use moderate light, etc.

Regards, 
Tom Barr 
“ end quote

I may be foolish, but for now I am relying on my PH controller and 
a visual observation of the plants and livestock in my tanks.
At he present time my pH in my largest planted tank is 6.3 which 
calculates to 75 ppm of CO2 saturation.

My plants pearl and the angels & ABN’s are happy. 

Just wanted to add my 2 cents.

Good day
Charles


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## Seattle_Aquarist (Mar 7, 2008)

Hi Charles,

I don't have a PH controller, or for that matter a solenoid, on my CO2 system. I guess you could call me "old school".

Drop checkers work very well for me, I find them to be simple, inexpensive, and effective. The "Blue, Green, Yellow" color indications are all I need to verify if I have enough CO2 available for good plant growth. I am not testing for CO2 levels in my tanks, I'm just trying to provide adequate CO2 for good plant growth. I also want to avoid large degrees of fluctuation that will promote algae growth. I don't believe that my plant's growth is materially effected by a CO2 level of 60 PPM verses a level of 45 PPM. With drop checkers I can also verify if I have fluctuating CO2 levels. 

Unfortunately some people use tank or tap water in their drop checkers which gives them inaccurate or inconsistent CO2 readings. I use 4.0 KH water (which I mix up using distilled water and Baking Soda) in my drop checkers along with the indicator solution. "Green" in one tank means the same as "Green" in the tank next to it.

I do agree with Tom Barr that observation is an important ingredient in successfully growing aquatic plants. If my plants aren't "pearling" after a half hour probably my CO2 is low. If my fish are "gasping" at the surface or lethargic, chances are my CO2 is high.


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## dmastin (Jun 27, 2009)

That's a great point about using a standardized fluid in your drop checker! The one I bought from GLA came with some 4 KH solution so I thought that was pretty cool. I wonder if I'm being a little conservative with my CO2. I have about 3 wpg T5, but I very very rarely see any pearling. Hum.



Seattle_Aquarist said:


> Hi Charles,
> 
> I don't have a PH controller, or for that matter a solenoid, on my CO2 system. I guess you could call me "old school".
> 
> ...


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## Seattle_Aquarist (Mar 7, 2008)

Hi dmastin,

With about 3 WPG I would think that you should definitely see "pearling" after your lights have been on for a while. While some of my plants seldom "pearl", like the anubias, others like my Ludwigia and tall crypts "pearl" within 1/2 hour of the light coming on. 

What color is the fluid in your drop checker? If you are not seeing "pearling" then you may want to slowly increase your CO2. I don't have a bubble counter, I just put my CO2 tube in the tank and count the number of bubbles in 10 seconds. Then I increase my count by no more than 10%, wait 48 hours, and re-check for "pearling" and bubble count.


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## dmastin (Jun 27, 2009)

Thanks so much for your thoughts SA! I have a wide variety of plants, so I'm sure some of them should be pearling. I apologize for hijacking, I'll post my CO2 experimentation via my journal thread. Thanks again!



Seattle_Aquarist said:


> Hi dmastin,
> 
> With about 3 WPG I would think that you should definitely see "pearling" after your lights have been on for a while. While some of my plants seldom "pearl", like the anubias, others like my Ludwigia and tall crypts "pearl" within 1/2 hour of the light coming on.
> 
> What color is the fluid in your drop checker? If you are not seeing "pearling" then you may want to slowly increase your CO2. I don't have a bubble counter, I just put my CO2 tube in the tank and count the number of bubbles in 10 seconds. Then I increase my count by no more than 10%, wait 48 hours, and re-check for "pearling" and bubble count.


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## cbwmn (Dec 18, 2007)

I do have three DC’s in smaller tanks with DIY CO2.
Maybe some day I’ll run a line through the attic and 
get a manifold & needle valves.

I use 4 kh solution that I bought from GLA.

It’s just a whole lot easier for me to rely on the controller.
I’ll learn my lesson If I ever suffocate some fish.

BTW, does a solenoid stick open very often?
I have the Milwaukee setup and so far I’m happy with it.
But I read where a lot of folks have troubles with their 
needle valves staying constant.

Charles

PS: supposed to hit 102 in El Paso today. Pool time!!!!


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## Dielectric (Oct 7, 2008)

Co2 charts and calculators are inaccurate.

these are the threads i was refering to.

http://www.aquaticplantcentral.com/f...?highlight=co2

http://www.aquaticplantcentral.com/f...?highlight=co2

http://www.aquaticplantcentral.com/f...?highlight=co2

http://www.aquaticplantcentral.com/f...?highlight=co2


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## Dielectric (Oct 7, 2008)

obviously i was pushing it way too far. my discus were all showing their stress bars, breathing heavy, and being sluggish. my plants were pearling like crazy though. i think it was just too much co2.

according to those threads i was well beyond 30ppm. according to that calculator i was at 210ppm.


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## ray-the-pilot (May 14, 2008)

I’ve said this many times here despite a lot of opposition but it is impossible to maintain, let alone figure out, the CO2 level in your tank without a CO2 controller and a drop checker. 

Slowly lower the set point on your controller (over a period of a week or so). Watch your fish and plants. As the CO2 increases the plants will start pearling and the fish will become sluggish (not necessarily gasping for air at the surface). Different plants and fish have different responses to high levels of CO2. You need to find a place between where the plants are happy and the fish are not. Once you locate it, your controller setting and drop checker act like a thermostat and a thermometer. 

If your controller set point doesn’t change and your drop checker doesn’t change color everything is OK. If either of these changes there is some problem that needs to be addressed.

I’ve checked the level of CO2 in my tank after setting it up as above. My drop checker is dark green and using 3 different methods to test the CO2 levels the best level for me is between 20 – 30 ppm.


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## ashappard (Jun 3, 2006)

perhaps the opposition is to the insistence that a controller is required.
theres more than one way to reach a happy balance between fish and plants - many do not even use solenoids. You could argue that a quality needle valve and a watchful eye are all that are needed. What's the value of a number (20 / 30 / 200ppm?) when the aquarium gives you ample visual cues?

for every method there is pro and con. In the end, use what works best for the goal in mind.


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## bosmahe1 (May 14, 2005)

I think it would be fun to have the ph controller and I would even consider buying it because, it would be fun to have. But currently I use both the drop checker and ph chart methods. After awhile observing pearling, plant growth, fish etc.. and both methods as a double check, you will learn a good set point for both. I know that when my ph reads 6.2 or 6.4 and my 4dh drop checker is lime green then my co2 is where I want it to be. The drop checker takes awhile (several hours) to react to change but, my ph chart may be used to tell me that plants are using alot of co2 if the dc is light green in the morning and dark green in the evening. From there I might determine if I want to tweak the co2 higher. I might determine this if I want to see more pearling from my Rotala. 

I don't necessarily need a digital display to tell me the proper co2 level. Doesn't the ph controller need to be calibrated as well? It doesn' mean I won't buy a controller after I've bought everything else.

I just don't think its fare to imply that the ph controller is necessary.


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## cbwmn (Dec 18, 2007)

bosmahe1 said:


> I think it would be fun to have the ph controller and I would even consider buying it because, it would be fun to have. But currently I use both the drop checker and ph chart methods.
> I don't necessarily need a digital display to tell me the proper co2 level. Doesn't the ph controller need to be calibrated as well? It doesn' mean I won't buy a controller after I've bought everything else.
> 
> I just don't think its fare to imply that the ph controller is necessary.


Yes, I have both 4.01 and 7.01 test solution and I check the calibration every month or so. It really doesn't take long.
My main reason for replying to this post is that I don't want to know that my pH level is "ABOUT" 30 ppm. I'd much rather know that it is exactly 60 ppm.

And due to old age, I find it difficult to observe the color in a DC installed in a tank. I have to remove it and hold it under a bright light. 
Thanks
Charles


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## Dielectric (Oct 7, 2008)

i have been using a controller for the past year and test it every month or so, and it has never needed to be recalibrated.


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## bosmahe1 (May 14, 2005)

cbwmn said:


> Yes, I have both 4.01 and 7.01 test solution and I check the calibration every month or so. It really doesn't take long.
> My main reason for replying to this post is that I don't want to know that my pH level is "ABOUT" 30 ppm. I'd much rather know that it is exactly 60 ppm.
> 
> And due to old age, I find it difficult to observe the color in a DC installed in a tank. I have to remove it and hold it under a bright light.
> ...


This is indeed a good point. I use the ph test as a doublecheck so I'm not that concerned about ppm that much. Looking for changes more than anything else. But looking at those color bars is annoying. Do I look at the test tube in daylight or under the flourescent bulb? It looks different in either case. Has anybody tried those pen type electric test dohickies for PH? Are they worthwhile?


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## ray-the-pilot (May 14, 2008)

bosmahe1 said:


> This is indeed a good point. I use the ph test as a doublecheck so I'm not that concerned about ppm that much. Looking for changes more than anything else. But looking at those color bars is annoying. Do I look at the test tube in daylight or under the flourescent bulb? It looks different in either case. Has anybody tried those pen type electric test dohickies for PH? Are they worthwhile?


I have two pen pH meters. One works well the other that I dropped doesn't. I keep it because it still can measure conductivity.

My DC is in the corner of my tank where it is easily visible. As I said, it is used to check my controller.

If there is someone here in product development, here is an idea for a better DC. Instead of using a pH indicator to measure the pH of your DC, put a tiny pH electrode in it. Since the solution in the DC is 4 deg. KH; the pH will be directly related to the CO2 in the DC. You could hook this up to a computer that gives a direct read out in CO2. OK it may cost a lot at first but that is how all good inventions start out!

BTW Controllers are used to control the CO2 level in your tank. They cannot be used to control the pH. Controlling the pH with CO2 is inefficient and possibly dangerous to your fish. That is why I call these devices CO2 controller, not pH controllers.


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