View Full Version : Sudden pH drop.
Dmitri Priimak
October 14th 04, 10:23 PM
Hi All.
I am somewhat new to this hobby. And today I made CO2 system with yeast
and was injecting bubbles with the power head and pH dropped from 7.2 to
6.2 withing about 4 hours. Luckily I don't have fish in the tank yet.
So, why did it drop so much? From what I read I did not expect to
dissolve much of CO2 by just bubbling it though water. Is there anything
wrong with my water? Is the hardness somehow related to it.
--
Dmitri Priimak
Szaki
October 15th 04, 12:09 AM
As I heared adding CO2 can change the PH of the water, so you have to
monitor closly.
KH, pH, and CO2
The CO2 content of your aquarium is important if you are growing plants
(though check out a discussion on which plants need supplemental CO2, and
which may actually do worse with it!). But CO2 is also of interest to the
general aquarist because it is intimately related to the water's carbonate
hardness (KH) and pH; dissolved carbonates will raise both KH and pH, while
addition of CO2 will lower pH. Here are some charts showing the relationship
between CO2, pH and KH, along with a discussion of the actual chemical
reactions. You can read CO2 content indirectly by from the combined pH and
KH readings, from a good test kit, or try this simple metering method.
A few plants are able to take in carbon directly from dissolved calcium
carbonate (a procedure called biogenic decalcification by some). This
procedure in turn may cause your pH to rise.
You can easily make your own carbonate buffer from common chemicals. You can
use Calcium Chloride to increase GH without changing the alkalinity and pH.
Some suggest you can use hydrochloric acid in extreme moderation to reduce
the buffering capacity of your water (this article also discusses an
empirical result of CO2 content vs. KH).
http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html
JS
"Dmitri Priimak" > wrote in message
...
> Hi All.
>
> I am somewhat new to this hobby. And today I made CO2 system with yeast
> and was injecting bubbles with the power head and pH dropped from 7.2 to
> 6.2 withing about 4 hours. Luckily I don't have fish in the tank yet.
> So, why did it drop so much? From what I read I did not expect to
> dissolve much of CO2 by just bubbling it though water. Is there anything
> wrong with my water? Is the hardness somehow related to it.
>
> --
> Dmitri Priimak
Dmitri Priimak
October 15th 04, 03:04 AM
Well. I just measured KH and it is around 5.5 thus according to the
chart you gave me link to it means CO2 was more than 100 ppm. But that
does not seem to be possible since all I was doing was spreading fine
CO2 bubbles with power head. Could it be that there were to many
bubbles? Power head was providing suction from DIY yeast reactor.
Dmitri Priimak
Szaki wrote:
> As I heared adding CO2 can change the PH of the water, so you have to
> monitor closly.
> KH, pH, and CO2
> The CO2 content of your aquarium is important if you are growing plants
> (though check out a discussion on which plants need supplemental CO2, and
> which may actually do worse with it!). But CO2 is also of interest to the
> general aquarist because it is intimately related to the water's carbonate
> hardness (KH) and pH; dissolved carbonates will raise both KH and pH, while
> addition of CO2 will lower pH. Here are some charts showing the relationship
> between CO2, pH and KH, along with a discussion of the actual chemical
> reactions. You can read CO2 content indirectly by from the combined pH and
> KH readings, from a good test kit, or try this simple metering method.
>
> A few plants are able to take in carbon directly from dissolved calcium
> carbonate (a procedure called biogenic decalcification by some). This
> procedure in turn may cause your pH to rise.
>
> You can easily make your own carbonate buffer from common chemicals. You can
> use Calcium Chloride to increase GH without changing the alkalinity and pH.
> Some suggest you can use hydrochloric acid in extreme moderation to reduce
> the buffering capacity of your water (this article also discusses an
> empirical result of CO2 content vs. KH).
>
> http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html
>
>
>
> JS
>
>
>
> "Dmitri Priimak" > wrote in message
> ...
>
>>Hi All.
>>
>>I am somewhat new to this hobby. And today I made CO2 system with yeast
>>and was injecting bubbles with the power head and pH dropped from 7.2 to
>>6.2 withing about 4 hours. Luckily I don't have fish in the tank yet.
>>So, why did it drop so much? From what I read I did not expect to
>>dissolve much of CO2 by just bubbling it though water. Is there anything
>>wrong with my water? Is the hardness somehow related to it.
>>
>>--
>>Dmitri Priimak
Szaki
October 15th 04, 07:13 AM
KH 5.5 is very low. How you measured it? Is that in ppm? My test strip shows
120-180 ppm KH is ideal.
Once I read, should be 3-4 bubbles / minute CO2 is a good rate. Some people
construct simple regulator.
JS
"Dmitri Priimak" > wrote in message
...
> Well. I just measured KH and it is around 5.5 thus according to the
> chart you gave me link to it means CO2 was more than 100 ppm. But that
> does not seem to be possible since all I was doing was spreading fine
> CO2 bubbles with power head. Could it be that there were to many
> bubbles? Power head was providing suction from DIY yeast reactor.
>
> Dmitri Priimak
>
> Szaki wrote:
>
> > As I heared adding CO2 can change the PH of the water, so you have to
> > monitor closly.
> > KH, pH, and CO2
> > The CO2 content of your aquarium is important if you are growing plants
> > (though check out a discussion on which plants need supplemental CO2,
and
> > which may actually do worse with it!). But CO2 is also of interest to
the
> > general aquarist because it is intimately related to the water's
carbonate
> > hardness (KH) and pH; dissolved carbonates will raise both KH and pH,
while
> > addition of CO2 will lower pH. Here are some charts showing the
relationship
> > between CO2, pH and KH, along with a discussion of the actual chemical
> > reactions. You can read CO2 content indirectly by from the combined pH
and
> > KH readings, from a good test kit, or try this simple metering method.
> >
> > A few plants are able to take in carbon directly from dissolved calcium
> > carbonate (a procedure called biogenic decalcification by some). This
> > procedure in turn may cause your pH to rise.
> >
> > You can easily make your own carbonate buffer from common chemicals. You
can
> > use Calcium Chloride to increase GH without changing the alkalinity and
pH.
> > Some suggest you can use hydrochloric acid in extreme moderation to
reduce
> > the buffering capacity of your water (this article also discusses an
> > empirical result of CO2 content vs. KH).
> >
> > http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html
> >
> >
> >
> > JS
> >
> >
> >
> > "Dmitri Priimak" > wrote in message
> > ...
> >
> >>Hi All.
> >>
> >>I am somewhat new to this hobby. And today I made CO2 system with yeast
> >>and was injecting bubbles with the power head and pH dropped from 7.2 to
> >>6.2 withing about 4 hours. Luckily I don't have fish in the tank yet.
> >>So, why did it drop so much? From what I read I did not expect to
> >>dissolve much of CO2 by just bubbling it though water. Is there anything
> >>wrong with my water? Is the hardness somehow related to it.
> >>
> >>--
> >>Dmitri Priimak
Dmitri Priimak
October 15th 04, 03:59 PM
My 5.5 is in dH ( degrees of hardness ).
In ppm it will be 5.5*17.86=98.23 ppm
Your KH in dH will be is from 6.7 to 10 dH.
Well, I guess I saturated water with CO2 juts by bubbling it. My mistake
was to assume that not much of it would be absorbed in such a way. So,
my question is. How do you recommend to rise KH?
--
Dmitri Priimak
Szaki wrote:
> KH 5.5 is very low. How you measured it? Is that in ppm? My test strip shows
> 120-180 ppm KH is ideal.
> Once I read, should be 3-4 bubbles / minute CO2 is a good rate. Some people
> construct simple regulator.
>
> JS
>
> "Dmitri Priimak" > wrote in message
> ...
>
>>Well. I just measured KH and it is around 5.5 thus according to the
>>chart you gave me link to it means CO2 was more than 100 ppm. But that
>>does not seem to be possible since all I was doing was spreading fine
>>CO2 bubbles with power head. Could it be that there were to many
>>bubbles? Power head was providing suction from DIY yeast reactor.
>>
>>Dmitri Priimak
>>
>>Szaki wrote:
>>
>>
>>>As I heared adding CO2 can change the PH of the water, so you have to
>>>monitor closly.
>>>KH, pH, and CO2
>>>The CO2 content of your aquarium is important if you are growing plants
>>>(though check out a discussion on which plants need supplemental CO2,
>
> and
>
>>>which may actually do worse with it!). But CO2 is also of interest to
>
> the
>
>>>general aquarist because it is intimately related to the water's
>
> carbonate
>
>>>hardness (KH) and pH; dissolved carbonates will raise both KH and pH,
>
> while
>
>>>addition of CO2 will lower pH. Here are some charts showing the
>
> relationship
>
>>>between CO2, pH and KH, along with a discussion of the actual chemical
>>>reactions. You can read CO2 content indirectly by from the combined pH
>
> and
>
>>>KH readings, from a good test kit, or try this simple metering method.
>>>
>>>A few plants are able to take in carbon directly from dissolved calcium
>>>carbonate (a procedure called biogenic decalcification by some). This
>>>procedure in turn may cause your pH to rise.
>>>
>>>You can easily make your own carbonate buffer from common chemicals. You
>
> can
>
>>>use Calcium Chloride to increase GH without changing the alkalinity and
>
> pH.
>
>>>Some suggest you can use hydrochloric acid in extreme moderation to
>
> reduce
>
>>>the buffering capacity of your water (this article also discusses an
>>>empirical result of CO2 content vs. KH).
>>>
>>>http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html
>>>
>>>
>>>
>>>JS
>>>
>>>
>>>
>>>"Dmitri Priimak" > wrote in message
...
>>>
>>>
>>>>Hi All.
>>>>
>>>>I am somewhat new to this hobby. And today I made CO2 system with yeast
>>>>and was injecting bubbles with the power head and pH dropped from 7.2 to
>>>>6.2 withing about 4 hours. Luckily I don't have fish in the tank yet.
>>>>So, why did it drop so much? From what I read I did not expect to
>>>>dissolve much of CO2 by just bubbling it though water. Is there anything
>>>>wrong with my water? Is the hardness somehow related to it.
>>>>
>>>>--
>>>>Dmitri Priimak
>
>
>
Brian S.
October 15th 04, 10:52 PM
Just kind of a side question off of Dmitri's,
Does anyone know the 'quality' or quantity of actual Co2 produced by a yeast
system?
For example, I have been running a yeast system now for about two weeks.
When it bubbles in, it will bubble in at an average rate of about one bubble
per 7-12 seconds. However, it seems that the Co2 sits in the "bell"
container that I have fastened to the side with suction cups forever.
Now, I got this "bell" container in my Jungle Fizz Factory which also came
with 16 Co2 tablets. When I use one of the Co2 tablets, it will bubble in
and fill almost the entire "bell" container up with Co2. In a matter of
two-three hours, ALL of this Co2 is disolved into the water.
But, I let the yeast production fill up the "bell" container as the Co2
tablets did, then I un-hooked the yeast Co2 generator to conduct my "test".
I let it sit for over 24 hours and only about HALF of the so-called Co2 was
disolved into the water.
So, basically I am wondering if yeast also expels other gases other than
Co2.
Brian S.
"Dmitri Priimak" > wrote in message
...
> Hi All.
>
> I am somewhat new to this hobby. And today I made CO2 system with yeast
> and was injecting bubbles with the power head and pH dropped from 7.2 to
> 6.2 withing about 4 hours. Luckily I don't have fish in the tank yet.
> So, why did it drop so much? From what I read I did not expect to
> dissolve much of CO2 by just bubbling it though water. Is there anything
> wrong with my water? Is the hardness somehow related to it.
>
> --
> Dmitri Priimak
Michi Henning
October 16th 04, 12:21 AM
"Brian S." > wrote in message
news:fEXbd.245812$MQ5.118394@attbi_s52...
>
> For example, I have been running a yeast system now for about two weeks.
> When it bubbles in, it will bubble in at an average rate of about one bubble
> per 7-12 seconds. However, it seems that the Co2 sits in the "bell"
> container that I have fastened to the side with suction cups forever.
>
> [...]
> But, I let the yeast production fill up the "bell" container as the Co2
> tablets did, then I un-hooked the yeast Co2 generator to conduct my "test".
> I let it sit for over 24 hours and only about HALF of the so-called Co2 was
> disolved into the water.
>
> So, basically I am wondering if yeast also expels other gases other than
> Co2.
Not that I know of. If there are any other gases, they'd make up only a tiny
fraction of the total. What is more likely, I suspect, is that you are seeing
air in your bell: when you initially set up the CO2 bottle, the air space above
the yeast mixture and the air in the tubing are, well, air. So, initially, your
yeast system will produce mostly air and, for a while, will produce a mixture
of CO2 and air. If you see your bell emptying only half way, that simply means
that about half of the gas you put in was air, and the other half was CO2.
If you let the yeast system run for a while (and keep the bottle and hoses
sealed,
so no air can get in), then empty out your bell and refill with what comes out
of the yeast system, I'd expect to see virtually all of the gas dissolve,
because
virtually all of the gas should be CO2. And CO2 cannot help but dissolve in
water, at least at the CO2 concentrations you need in a planted tank. I'm
not aware of any mechanism that could prevent CO2 from dissolving, unless
you saturate the water with CO2, at which point no more CO2 will dissolve.
(But, by the time you reach saturation point, all the fish will be long since
dead...)
Cheers,
Michi.
--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com
Rick
October 16th 04, 04:05 AM
"Dmitri Priimak" > wrote in message
...
> My 5.5 is in dH ( degrees of hardness ).
> In ppm it will be 5.5*17.86=98.23 ppm
> Your KH in dH will be is from 6.7 to 10 dH.
>
> Well, I guess I saturated water with CO2 juts by bubbling it. My mistake
> was to assume that not much of it would be absorbed in such a way. So,
> my question is. How do you recommend to rise KH?
>
> --
> Dmitri Priimak
>
one of the problems with DIY CO2 systems is the inconsistency of the amount
of gas and PH swings. When you first mix up the batch it produces at a high
rate which slowly diminishes until it runs out. If you use DIY you need two
bottles and alternate them so that you can keep your levels reasonably in
the ball park. I don't think at about 100 PPM that there is any need to
raise your KH which in turn will raise your PH. I would shoot for about
30ppm of CO2 which should mean that your PH would need to be around 6.9 or
7.0. In my planted tank my KH is lower than yours but my PH is higher.
Rick
Brian S.
October 16th 04, 04:45 AM
Thanks for the idea Michi.
Actually, I performed this test about one week after the Co2 generator was
up and running. I had thought about the oxygen at the top of the bottle
getting into the "bell" so that is why I tried the experiment after it was
setup for a week.
Maybe there is something else in these Co2 tablets that cause it to disolve
in the water faster...
Brian S.
"Michi Henning" > wrote in message
...
> "Brian S." > wrote in message
> news:fEXbd.245812$MQ5.118394@attbi_s52...
> >
> > For example, I have been running a yeast system now for about two weeks.
> > When it bubbles in, it will bubble in at an average rate of about one
bubble
> > per 7-12 seconds. However, it seems that the Co2 sits in the "bell"
> > container that I have fastened to the side with suction cups forever.
> >
> > [...]
> > But, I let the yeast production fill up the "bell" container as the Co2
> > tablets did, then I un-hooked the yeast Co2 generator to conduct my
"test".
> > I let it sit for over 24 hours and only about HALF of the so-called Co2
was
> > disolved into the water.
> >
> > So, basically I am wondering if yeast also expels other gases other than
> > Co2.
>
> Not that I know of. If there are any other gases, they'd make up only a
tiny
> fraction of the total. What is more likely, I suspect, is that you are
seeing
> air in your bell: when you initially set up the CO2 bottle, the air space
above
> the yeast mixture and the air in the tubing are, well, air. So, initially,
your
> yeast system will produce mostly air and, for a while, will produce a
mixture
> of CO2 and air. If you see your bell emptying only half way, that simply
means
> that about half of the gas you put in was air, and the other half was CO2.
>
> If you let the yeast system run for a while (and keep the bottle and hoses
> sealed,
> so no air can get in), then empty out your bell and refill with what comes
out
> of the yeast system, I'd expect to see virtually all of the gas dissolve,
> because
> virtually all of the gas should be CO2. And CO2 cannot help but dissolve
in
> water, at least at the CO2 concentrations you need in a planted tank. I'm
> not aware of any mechanism that could prevent CO2 from dissolving, unless
> you saturate the water with CO2, at which point no more CO2 will dissolve.
> (But, by the time you reach saturation point, all the fish will be long
since
> dead...)
>
> Cheers,
>
> Michi.
>
> --
> Michi Henning Ph: +61 4 1118-2700
> ZeroC, Inc. http://www.zeroc.com
>
Dmitri
October 16th 04, 07:09 AM
Rick wrote:
> "Dmitri Priimak" > wrote in message
> ...
>
>>My 5.5 is in dH ( degrees of hardness ).
>>In ppm it will be 5.5*17.86=98.23 ppm
>>Your KH in dH will be is from 6.7 to 10 dH.
>>
>>Well, I guess I saturated water with CO2 juts by bubbling it. My mistake
>>was to assume that not much of it would be absorbed in such a way. So,
>>my question is. How do you recommend to rise KH?
>>
>>--
>>Dmitri Priimak
>>
>
> one of the problems with DIY CO2 systems is the inconsistency of the amount
> of gas and PH swings. When you first mix up the batch it produces at a high
> rate which slowly diminishes until it runs out. If you use DIY you need two
> bottles and alternate them so that you can keep your levels reasonably in
> the ball park. I don't think at about 100 PPM that there is any need to
> raise your KH which in turn will raise your PH. I would shoot for about
> 30ppm of CO2 which should mean that your PH would need to be around 6.9 or
> 7.0. In my planted tank my KH is lower than yours but my PH is higher.
>
> Rick
>
>
I see. One thing I want to mention is that my pH in tap water was around
above 8 to lower it I used Seachem "Liquid Acid Buffer" which brought my
pH down to about 7.2. This suppose to skew tables which indicate CO2
level isn't? And by the way do you know exactly how it (Liquid Acid
Buffer) works? It is written on a bottle "Converts alkalinity (KH) into
CO2". Does is it mean that it brakes CO3 and HCO3 into CO2 and whatever
left over from it? If so what chemical is used in that "Liquid Acid Buffer"?
--
Dmitri Priimak
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