my PH level going crazy or am i?

[OasisKeeper]

CO2 ah, is CO2

Here's carbonic acid: H2CO2

Here's carbonate: CO3

Here's Bicarbonate: HCO3 (its the middle guy between those first two)

Where did the H's and the extra O go? Oh yeah, H2O

 

[bs6749]

Here's the thing. Tom Barr claims that a changing pH due to a change in KH is worse than a change in pH due to CO2 injection being halted and here's why. He claims that there are salts that put carbonate and bicarbonate ions back into the aquarium when water from the tap is placed into the aquarium. This is true, I have no doubt that there are salts being added to the tank from the water. These salts then effect the KH level in the tank as the amount of carbonate ions and bicarbonate ions drastically increases. He is claiming that it's these salts that are hurting the fish and they can be detected because the pH will increase. He's not saying that the pH is what is killing them if you read the article, he's saying it's the salts, which can and will effect the pH as I've already stated. The fact that they lower the pH, however is irrelevant. An analagous situation of irrelevance would be to have a 55g tank that is set to 88 degrees stocked with fish. Then, say you add to the tank 1 gallon of a "chemical x" that is frozen at 20 degrees and it kills all of the fish inside while lowering the temperature of the tank to 84 degrees. Is it the temperature decrease of 4 degrees that killed the fish or was it the chemical X (obviously) that killed them? We all know a sudden decrease in temperature can kill fish (shock) but what we need to know is by how much the temperature must be different in order to cause harm/death. The same thing applies to the relationship of pH and KH. pH swings can harm/kill fish but it's more realistic to expect death to occur when the fluctuation is about 3 whole points or more rather than .75 which is "stressful" at the least.

 

[OasisKeeper]

that a change in pH resulting from a shift in CO2 is NOT AS HARMFUL as a shift in pH from a change in hardness.

Lets be clear, everybody agrees that dissolved solids changes are best avoided or at least slowly introduced so that the fish can adapt. What we are not in agreement on is if a shift in pH, where dissolved solids remain unchanged, is harmful with wide open parameters of how much, how fast, and how often.

 

[OasisKeeper]

To try and return to the original subject a bit... Has anybody tried using two needle valves, one for day injection, one for night? It would be possible to set this up with a single solenoid if you plumb it up correctly.

 

[SpeedEuphoria]

To try and return to the original subject a bit... Has anybody tried using two needle valves, one for day injection, one for night? It would be possible to set this up with a single solenoid if you plumb it up correctly.

Just to lessen the PH swing?

 

[OasisKeeper]

Just to lessen the PH swing?

Yes, that is what I was thinking. Poor man's controller, so to speak.

 

[DSenn]

That posting with Tom Barr has him saying that a fish going from hard to soft water is more easily tolerated than going from soft to hard. I just wanted to clarify that. I am going to start another thread with the whole CO2/pH/KH nonsense. I feel like I have taken over this thread with my silly questions Sorry.

 

[sldp999]

thanks guys, for confusing me more.LOL
so the general question is, should i leave my pressurized co2 on at NIGHT or just leave it on the day.??
thanks

 

[SpeedEuphoria]

If you have a solenoid on a timer then use it as save the CO2.

You dont see these people saying they have fish dying all the time running these setups.

Like I said TDS and KH are more critical things to keep stable IMO than PH.


Now my turn to hijack!


For people running CO2 at higher levels, do you acclimate new fish the same way you would if you did not use Co2? Just make sure and take plenty of time using the drip method should be fine AFAIK. The way i see it the more things that are different, would seem the more stress on new fish. Like KH/TDS/then the waters CO2 content

 

[OasisKeeper]

thanks guys, for confusing me more.LOL
so the general question is, should i leave my pressurized co2 on at NIGHT or just leave it on the day.??
thanks

Decision tree:

1) Are you concern about CO2 cost?
If yes goto 4, if no goto 2

2) Are you concerned about the pH swings?
If yes goto 3, if no goto 4

3) Does pH go too low if I leave it on at night?
If yes goto 4, if no goto 5

4) Leave it as it is (off at night)

5) Leave it on at night

The final option is add a controller or other (dual needle valve) system.

 

[bs6749]

Decision tree:

1) Are you concern about CO2 cost?
If yes goto 4, if no goto 2

2) Are you concerned about the pH swings?
If yes goto 3, if no goto 4

3) Does pH go too low if I leave it on at night?
If yes goto 4, if no goto 5

4) Leave it as it is (off at night)

5) Leave it on at night

The final option is add a controller or other (dual needle valve) system.

WOW! Like a choose your own ending story!!!! : ) LOL

 

[SpeedEuphoria]

Does pH go too low if I leave it on at night?

Thats the thing people need remember, if you leave the CO2 constant throughout the day and night, the CO2 will be higher/est at night when plants dont use it and fish certainly dont want it and your PH will drop further.

 

[OasisKeeper]

Thats the thing people need remember, if you leave the CO2 constant throughout the day and night, the CO2 will be higher/est at night when plants dont use it and fish certainly dont want it and your PH will drop further.

I guess one further comment that goes with this is: You really want to have a decent Kh in any case. 2 dKh or better I'd say. And if you don't know what your KH is, well, you need to.

The op's top pH suggests plenty of buffer but still, I'd test.

With a good buffer, the swing you will get at night leaving it on will only be equal to the plant's daytime consumption, which I am willing to bet will be significantly less then the swing from say 20 or 30 ppm to 2 (atm).

Edited to add Fuel to the fire the same discussion, from eight years ago.

 

[BillD]

Can anyone point me to any documentation of verified pH shock? It is a term that is used ad nauseum, and I have seen it stated in a publication that there does not exist a single documented case of pH shock killing fish. Can anyone here prove or disprove it?

 

[SpeedEuphoria]

DSen; no more threads on this, lets finish it here! LOL
Here's my contribution

http://aquanic.org/publicat/usda_rac/efs/srac/464fs.pdf

ALALINITY & HARDNESS IN PONDS

Water Hardness and Fish Health

Fundamentals of Aquacultural Engineering - Google Book Search
In that one I found this very interesting as it is what I have been seeing with people doing fishless cycles

In systems where oxygen is not limiting, the conversion of ammonia to nitrite is the rate limiting step in the total process. Nitrite is converted to nitrate fairly rapidly, therefore, in most natural systems nitrite concentrations are usually of no concern....

Oh if you want to research further this is what i searched in google "PH Carbon Dioxide Alkalinity Hardness effect on Fish", also try google scholar if you have not, it can be found under the advanced search in google

 

[OasisKeeper]

I don't think they liked your cut and paste Speed. They changed the double headed arrows to little icons .

 

[jsoong]

Yeah, I find strange things with this board when I do cut & paste as well ....

The equation should be:

CO2 + H2O <--> H2CO3 <--> HCO3- + H+ <--> CO3-- + 2H+

CO3-- will precipitate out in the presence of Ca++ <at alkaline pH>

DSenn: As you can see from the equation, when carbolic acid dissociates, it forms 1 HCO3- for each H+. HCO3- is what you measure as KH. So in effect, carbonic acid makes its own KH, that's why the KH doesn't drop with addition of CO2.

I suspect that pH drop from CO2 is less a problem precisely because it does not deplete KH. Other acid (ie metabolic acidosis) do consume HCO3, and pH does not drop until it is nearly gone. We must remember that it is not external pH that causes problem. It is internal cellular pH that governs enzyme functions. The fish tries to maintain the intracellular pH against changes in external pH. It is likely easier if the buffering system is intact.

 

[SpeedEuphoria]

I don't think they liked your cut and paste Speed. They changed the double headed arrows to little icons .

Nope, it copied correctly, the source is the link above the quote, and thats how its stated in the source, I did not even look at it.

 

[OasisKeeper]

Nope, it copied correctly, the source is the link above the quote, and thats how its stated in the source, I did not even look at it.

I'm not saying it's incorrect. Just saying, the first time I looked at both your cut and paste and the source materials this morning, it had double headed arrows, where the forum icons show in the source now.

Then, 30 minutes later, the icons replaced the double arrows.

It originally looked like jsoong's, which is correct in showing the reaction is bidirectional.

Edited: Ah.. its my browser.. I don't use brand X

 

[SpeedEuphoria]

Edited: Ah.. its my browser.. I don't use brand X

Which one's that again?