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Where are you using the CO2 at? Outside? Just curious as to the temp of 60.

Either way, the temp only decreases the preasure in the tank (not the amount). Because any gas is more active when warmer than cold, the preasure will be increased with heat, and decrease with cold. But, will still be the same amount, and will still be a gas until liquified. Which CO2 temp to liquify is well below 0 degrees (exact temp is a lost file in my out dated computer, or in other words my brain, LOL) Did you accidently get something into the air line, that may be clogging it? Now I know this may be a stupid question, but hey it does happen; Did you double check and make sure it is turned on?

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There is always a bigger fish...

Well it's a DIY one that I've been running for a few months, never really had trouble with it...I'll have to double check that nothings blocking it when I get home, don't know what could have gotten in there though...

And it's 60 because that's what my house temp is overnight in winter....and most of the day for that matter, since I'm never home .

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Okay it's winter () here in east coat USA....I replaced my co2 mix yesterday, but I'm still not getting any bubbles....which I found slightly odd. Only thing I can think of is that an air temp of 60F is too cold for the little beasties.
Anyone know for sure

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There's an issue I'd like to raise here regarding the relationship between KH, CO2 and pH. The common belief by most of us is that a higher KH is good as the pH swings will not be as extreme as they would with a lower KH. Think about this for a second, do you agree?

Now, have a look at the ph/KH/CO2 relationship chart at the krib (http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html):

Let's say that a certain tank has a pH of 7 and 1.5 dKH. That is 4ppm CO2 (close to equilibrium). CO2 is then added to the tank to a level of 28ppm. The pH will drop to 6.2. A shift of 0.8 in pH.

Another tank, with 15 dKH and 4ppm CO2 will have a pH of 8. Once we raise the CO2 to 28ppm, the pH will drop to 7.2. A shift of 0.8 in pH. The exact same shift as the above tank with only 1.5 dKH.

So, KH doesn't control how extreme pH swing will be, it only controls the region of the swing within the pH chart.

Therefore, I think that it doesn't really matter what my KH is when it comes to worrying about pH swings (which, in my opinion, stress the fish). The pH swing will be the same anyway, it might only be within the safe pH region. Then, when I should worry about keeping the amount of CO2 in the water stable during the night, regardless of how I do it (I'm still experimenting on this one, i'll let you know what my conclusions are when I'm done).

Okay then, this is how I interpret the chart according to my logic. If anybody thinks I'm wrong, I'd love to hear what they think and why.

So how and why do fish live in densely plants regions that have no CO2 added??

You do not have to do CO2, it is not a requirement to keep plants. It just encourages growth. But with it you need to increase the need nutrients for the plants, as well as the needed lighting, or the plants will not use it. They need all three to work. Another thing, many plants come from area high in CO2, such as stagnent lakes, and bogs. In these areas, there is little surface movement, thus less gas exchange, and thus a build up of CO2.

pH goes from 6 to 10 in some places.
2 full units is very common.
Tons of fish swimming by.

I know of no where that the ph goes from 6-10. Please tell us of your resource. As for the 2 full units of change, well there are a FEW places this does happen, but it is not VERY COMMON at all.

Why do Discus bred in non CO2 planted tanks?

I am hoping you meant "non added CO2", because all tanks, and water environments in nature have CO2 in them. I guess the reason they do this, is because they do it in nature. You really lost me on that question.

pH induced shifts from CO2 does not cause any harm near as I can tell.

How can you tell that it does not cause any harm? Just because you do not see any harm, does not mean it is not there. Any kind of ph swing CAN harm fish, though not saying it always does. But some fish, will die from just one degree change for too long of a period. I have seen fish with ph burns on them, and it is usually fatal.

If you add a bunch of baking soda or other chemicals to alter pH quickly, that can kill the animals.

So very true, so very true. But, in the same understanding, if you add fish from/in one ph water, to water higher/lower in ph, this can kill them quickly as well. This is one of the big reasons you should slowly add water to the bag of new fish, when aclimating them.

CO2 pH shifts do not seem to cause any issues for fish/critters in and of themself.

A ph shift is a ph shift. Wether it is caused by vinager, baking soda, or CO2. ph is ph, and there is no difference in a ph swing caused by CO2 vs the other two. As for you statement, well tell that to the dozen of so pairs of wild Apistos I have lost, because I put them in a planted tank with CO2 running. Only did I realize what was happing to them, because those that I put in tanks without CO2, lived and bred for me.

Last edited by ACIDRAIN at 28-Nov-2004 20:33

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There is always a bigger fish...

So how and why do fish live in densely plants regions that have no CO2 added??

pH goes from 6 to 10 in some places.
2 full units is very common.
Tons of fish swimming by.

Why do Discus bred in non CO2 planted tanks?

pH induced shifts from CO2 does not cause any harm near as I can tell.

If you add a bunch of baking soda or other chemicals to alter pH quickly, that can kill the animals.

CO2 pH shifts do not seem to cause any issues for fish/critters in and of themself.

Regards,
Tom Barr



Regards,
Tom Barr

Hi,
As I said, the debate continues...

To inject, or not to inject, that is the question.

Depending upon your KH the pH shift will not be
serious enough to stress the fish. Depending upon
your bioload (how heavily stocked your tank is) your
fish will not be affected in the least by the small amount
of increase in CO2 saturation within the tank overnight.

Again it is a decision you can make predicated on the
KH and the stocking level of the tank.

It's your call.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

I am getting lost in all your posts. Lets see, you are all worried about ph swings. And the only swing discussed is that of an upward value. The discussion thus far has been, if I turn off my CO2 and the CO2 drops then my ph will rise. OK, now the understanding of plants actually respiring and taking in O2 and giving off CO2 at night, is the reason for someone wanting to turn off he CO2 at night. Because if you are adding CO2, and have a set level you like, then at night the plants start adding additional CO2, then the CO2 levels rise, and the O2 levels drop, and thus could cause the ph to drop. ph dropping is also a ph swing.

So, in the end, leaving your CO2 on all night long, can cause an increase in CO2, a decrease in O2, and the ph to drop.

Turning the CO2 off at night, can help keep a more stable environment within the tank, because the CO2 will be given off by the plants and will compensate for the turning off of the CO2 regulator. Plants and fish will have more O2, because there will not be a saturation of CO2 keeping the O2 out of the water.

Basically figure something like this; Leaving your CO2 on during the night hours, it is like having a second CO2 (plants) turn on during the night hours. And yes, depending on the surface aggitaion of your tank, could double the CO2 levels by morning.

I keep mine on all night, as I don't have any silinoids and such to turn them off, so I have an air stone that turns on a couple of hours after the lights are off, and turns on just before they come on.

_____________________________________________________________

There is always a bigger fish...

Hi,
There will always be a tendency for the pH to shift
during the darkened hours. How much, a lot, a little,
or nil, depends upon the Carbonate Hardness (KH) of the
tank. The Carbonate will buffer the swing, and if high
enough will completely "absorb" the swing.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Babel:

I've made an experiment tonight: I've left the CO2 running and aerated during the night. First thing I woke up this morning I checke the pH. Then few hours later, and again after few hours. There was no pH swing, at least not detectable.

The next step would be to try something I've tried once (when I was still using yeast) which was to put the air stone inside the cansiter of the filter (therefore minimising surface disturbancein the main tank) while turning the CO2 off and checking pH to see if it swings. If it doesn't, I'll do it that way, so I can save few quids on CO2. If it does swing, I'll keep running through the night.

As for yeast, you can't really turn it off during the night, can you? So I think you don't have a lot to worry. Although the production of CO2 will slow down during the night, the plants will compensate by producing CO2 themselves. At least in theory it sounds right, maybe you ought to test it in practice.

Whetu:
The only drawback I see in our plan are gasses. If the yeast would be eating all your sugars for you, you will be producing quite a lot of CO2. However, that maybe utilised as well... I remember reading once about a girl who injected CO2 into her tank by breathing into a huge nylon bag (while doing some sport), and then pumping that with an air pump into her tank. She claimed she got good results. Maybe with out method we can pump our excessive CO2 into the tank (burping or otherwise). Think about all the money we would save! On the one hand -- self sustainable diet (as the yeast will actually grow inside you); on the other -- free CO2 for our tanks! With the money we'll save we could buy really expensive sweets, which will actually feed the yeast. I reckon we might even get a Nobel prize for that!

untitled

The problem is it wouldn't eat up the fat! Ooooh but it would eat the sugar... before I digest it...
*eats a package of yeast*

ERrr actually that was my point. That the CO2 production wasn't killed or stopped compleatly due to the cold temperature, rather it was just slowed. Combined with the ideas put forth in the thread re: the lights, make sense, however I'd worry about the issue of ph swings.

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I would never argue with chemists and mothers, especially not mothers, and I've never even baked bread. I don't even have a bread machine. But here are few thoughts.

Dough will still rise in the fridge because the yeast is still alive (we keep yeast in the fridge and it doesn't kill it). However, and we need you to ask your mum if that is true, would dough rise slower in the fridge than it would on a work top basking in the summer sun? I guess it would, because the production of CO2 is (as far as I know) a function of temperature. More CO2 if the yeast is warmer, unless you kill it (www.exploratorium.com say that yeast will die at 130&#176;&#8211;140&#176; F/55&#176;&#8211;60&#176; C).

Your problem, if it wasn't for a hole in the tube, could be that the room temperature is too cold for the yeast to produce ENOUGH CO2 to create ENOUGH pressure to come out of the other side of the tube in the tank. But as we know, your case was different. Another solution, if temperature is the problem, is too add more yeast and therefore have more activity. On the other hand, this things are so hard to regulate, that I just gave up and bought a professional CO2 set.

Again, this is no argument. Just since starting adding CO2 I realised how fascinating yeast is (I am a geek, I know!). I even discovered that you shouldn't eat yeast because it will multiply in your stomach and rob you off your nutrients. I think we're onto something here... Maybe we could promote that as the next trendy diet after Atkin's and make lots of money?

Well, I'll stop ranting now.

It's amazing what parents are good for .
Asked my step-dad when I was home for thanksgiving (he's a chemist) and my mom was in the kitchen with us as well.... what was decided on was that yeast and sugar will continue to react till frozen. As my mom reminded me, bread dough that's stored in the fridge will need expanding room for when it rises.

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I will try to leave the CO2 on tonight, and see what is the pH tomorrow morning. I have to aerate my tank during the night, or the fish gasp, CO2 injected or not. The tank is actually understocked, but if I don't aerate it during the night, they gasp.

What worries me is the constance change in pH between day and night, but if keeping the CO2 running all night long will eliminate a change in pH, then that should be the way to do it.

My bottle actually comes with a solendid valve, which makes it easier to turn off and then on without having to get the exact same position the next day, my concern is really pH swings.

Thanks, I'll see how it goes. I'd rather waste CO2 than stress my fish, so if keeping it running at night means healthier fish, so be it!

Hi,
To inject or not to inject has long been a topic of
discussion and even argument on several forums.

The pH swing is not good and can stress your fish.

The discussion is prompted by several arguments.
First, after a given time, with the lights out,
plants switch from consuming CO2, to giving off CO2.
Many are concerned that:
A. It is a waste of gas.
B. The increased CO2 can harm the fish because the
O2, is depeleted.

If you turn off the gas, and in some cases folks even
turn on airstones, you drive off the CO2 returning the
tank to about 5mg/l, which is roughly equilibrium.
When you turn it back on, asside from the mechanics
of turning the valve to exactly the same place (amount)
as the day before, you still have to bring the saturation
back up to your desired level. If you leave it on, and
DO NOT aerate, then you don't "waste" as much gas bringing
the tank back to the desired saturation. IMO you actually
save gas.

If you leave the gas on, and do not aerate, you should
check your tank just before the lights come back on.
At that point CO2 should be at its highest, and IF there
is going to be a problem with the fish, this is when you
should see it. If they are gasping at the surface for
air, like a tank full of feeder goldfish in a LFS just
after they are placed in the tank, then yes, you do have
a problem. And, the problem is not the CO2 injection, it
is because you have far too many fish in a given quantity
of water.

As you probably have guessed, I have a bottled system.
I use a 10lb bottle, and inject at just slightly over
1 bubble/second. I run it 24/7/365, and at that rate
it depeletes the bottle in about 8 months. It takes
$9 and some change for tax, to refil it. My tank is
understocked and the pH swing is about 0.2 between
lights on and off. I have a two stage regulator, and
set the first stage at a one pound, and use a needle
valve to adjust the flow down to slightly over
1 bubble/second. Turning off the needle valve, and
then returning it to the same place is a tedious task
and would be necessary to return to the exact same point
as the day before.

You could use a solenoid connected to a timer. Connected
after the regulator, it would act as an on/off switch for
the gas and eliminate the need for daily adjustment.

In short, the decision is up to you. If it makes you
"feel good" then go ahead and turn it off and on, but
it is not necessary in a tank with adequate KH and
normally stocked.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

I hope you don't mind me stealing this thread, sort of, but it's related. This is mainly regaring Acidrain's last post.

Let's take my tank for example. I have a JBL proflora 2 system. My KH is 6 dKH. During the day I add CO2 and my pH is 7, which means I have 24ppm CO2. I shut it off during the night, when I turn off the lights, and I also aerate the water.

So, if my CO2 drops during the night to let's say 6, then my pH rises to 7.6. That seems to me to be a stressful swing in pH for my fish.

Now, to my question (sort of). Have I got anything wrong here? Anything I've neglected in my calculations? If not, am I not better off with leaving the CO2 on during the night as well?

As well, the sitting it on the lights would actually work well for the entire tank and its inhabitents. As when the lights were out, the temp would drop, and the CO2 would decrease probably. Thus, no CO2 spikes when the lights are out. And thus, no change in the ph when the lights go out.

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There is always a bigger fish...

Or you could just have a small hole in the silicone ...since I can't seem to unclog my silicone and reseal it, I just might go with the excel anyway....good idea whetu ....not sure how I'd swing it though, since I cover my tank .


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Just sit it on top of the lights, or even just on top of the tank. That's what I do in winter