co2

[Roediger]

I have a 10 gal , 106 fluval canister. pressure co2. 2t5 lights 17 inch distance from substrate.

my question is can co2 drop from 7.6 to 6.0 in 2 hrs and drop checker be aqua color. my readings have been 6.0 every time like Clive has said to test it. just want to make sure i am in the right path instead of thinking my drop checker has to be green for it to be good ?

Thank you.

 

[ceg4048]

Roediger,
pH rate of change, as well as the amount of change is dependent on how much buffering is in the water you are testing. The amount of buffering is also referred to as the Alkalinity, sometimes erroneously called KH (carbonate hardness). If the Alkalinity is low, then the water's resistance to pH change is also low.

So, for example, suppose there are two water samples, the first with an Alkalinity of 12 and the second with an Alkalinity of 1.

If we dissolve exactly the same amount of CO2 in both samples, the sample with Alkalinity 12 will not change it's pH very much, but the sample with Alkalinity 1 will drop the pH drastically.

If you have a KH test kit then measure the KH and compare that KH value to the KH in your DC.

The DC water should typically be RO or Distilled water which is adjusted to a KH of 4.

You have not told us what kind of water is in your DC.
You have not told us what the KH of your tank water is.
We're not sure how you are measuring pH, i.e. with a test kit solution, simple test strip, or pH pen.
if by pH pen we do not know it's quality or even if it has been calibrated correctly
So we do not know the accuracy of your pH measurement.

Also, the DC takes a couple of hours to respond.
When you observe the DC color, it is telling you what the pH in the tank water was a couple of hours ago.

That's why we instructed you to take direct pH measurement of the tank water and to compare the change in pH over time.
That gives you a more accurate idea of the behavior of the gas.

Because of these unknowns, everything is a lottery and the best we can say is that "Yes it is possible, but we do not know in your specific case what is going on due to missing information"

Cheers,

 

[Roediger]

Thanks Clive.

I do have Kh test solution kit, will test tomorrow.
my drop checker is a fluval solution that came with the drop checker kit.

Thanks again!

 

[Roediger]

Hello. so I tested KH and it turned yellow in 3 drops. and Ph is around 6.4 6.2

 

[ceg4048]

so I tested KH and it turned yellow in 3 drops.

OK, but what does this mean according to your test kit instructions?
If I had to guess, I'd say that the Alkalinity is around 2 or 2.5 but I shouldn't have to guess.
If your Alkalinity is indeed somewhere around 2 then that would explain why the pH dropped from 7.6 to 6.0 in 2 hours as you mentioned.

Cheers,

 

[Roediger]

reading instructions its saying i have low KH. and i should use buffers to bring up Ph and increase KH correct?

but my readings were done after co2 has ran for few hrs

 

[ceg4048]

reading instructions its saying i have low KH. and i should use buffers to bring up Ph and increase KH correct?

No.

This is how beginners get ensnared in the spiders web and spend the rest of their lives running on the little hamster wheel that goes to nowhere.

So that test kit doesn't even return a number, like 3 or 4 or 10?
It just says low medium and high?
I suppose it doesn't offer any explanation as to why it thinks your pH needs to be higher?
Just get into the habit of spending more money for buffers and worship at the Temple of pH, like all the other hamsters, right?

Here is my advice; Throw that test kit away and from this day onward, never worry about what your pH is, because your fish will not care about what your pH is and neither will your plants.
The only reason we are measuring the pH changes is so that we can get a better understanding of what the CO2 is doing, because fish and plants definitely care about the CO2. The fish don't like it but the plants love it, so you have to add enough CO2 so that the plants are satisfied but not so much that the fish are dissatisfied.

As far as the KH, you only need enough alkalinity so that the devices that you use to measure pH will return accurate values. If the alkalinity is zero, for example the pH measurements will not be accurate.
But we don't really know if the alkalinity is zero, do we. We only know that it's "low", which we figured out just by looking at the amount that the pH dropped.

Can people see why I despise all hobby test kits? This piece of junk didn't tell us anything we didn't already know, and it returns lame values - and it probably cost an arm and a leg. Ridiculous.

Cheers,

 

[Roediger]

Hello, Yeah it has no directions just says to count drops and thats how much KH is and to look up what the PH is and what ever numbs they both match thats the amount i have.