Adding CO2

Tug

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City water is slightly alkaline with a pH 7.6 and I want to add CO2. How long should this take? How do I keep from killing any fish? Will it give me a pH6.6? Will KH keep the CO2 from bringing down the pH? What's the buffer do anyway and what is it?
 

VaughnH

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Beautiful catfish you have there!

CO2 added to the water doesn't stay there. It is constantly lost from the water surface, so a few hours later the amount in the water is back to near what it was before you added some. That is true no matter what the KH of the water is, and no matter what else you add to the water.

The baking soda some people add to their DIY CO2 generator is just to keep the yeast/sugar/water solution from becoming too acidic for the yeast to grow. It has no effect on the CO2 in the tank water.
 

Tug

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Great! So if the KH stays the same the pH will let me know the amount of CO2 in the Tank. Thanks !
Tug;32520 said:
How do I keep from killing any fish?
Oh, I began counting bubbles ten days ago, have not added any fish and it might be another seven days before I do. What's next?
 

VaughnH

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A single DIY CO2 bottle is extremely unlikely to generate enough CO2 to kill your fish. If you get a drop checker and fill it with 4 dKH distilled water and a couple of drops of pH reagent, the water in it will be green when you have about enough CO2, and very yellow when you have too much.
 

Tug

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To make 4 dKH distilled water would .98 grams of baking soda (sodium bicarbonate) for each quart of distilled water work for accurate testing?
 

VaughnH

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I don't know what the amount of bicarbonate of soda needed is. But, if you have a KH test kit, that isn't too old, you can check the KH after you mix it, and verify it yourself. You don't need absolute accuracy. If it is between 3.5 and 4.5 that is fine for use in a drop checker.
 

SuperColey1

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Baking Soda is different to Bicarb!!!! Need to make sure you get Bicarb.

I made mine adding 6g Bicarb to 5ltrs DI = 40dKH
10ml of 40dKH added to 90ml DI = 4dKH

Making the first solution so large and then taking a little of it to make 100ml of the final solution means much less room for error/variation.

i.e. If you were to add 0.6g to 500ml and were 0.05g (8.33% error) out then it is less accurate than being 0.05g out on 6g (less than 1% error)

AC
 

abcemorse

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I think I'd add more plants or let the cycle complete entirely before adding fish...just to be sure :)
 

Tug

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Yeast growing in my tank?

I am growing a white slime on the bubble counter emanating from the tube of my DIY CO2 generator. Anyone know what this might be?

P1140001.jpg
 

imeridian

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SuperColey1;32610 said:
Baking Soda is different to Bicarb!!!! Need to make sure you get Bicarb.

In the United States baking soda is sodium bicarbonate. Perhaps you were thinking of baking powder, or maybe it's just a nomenclature difference between countries.
 

kid creole

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SuperColey1;32610 said:
Baking Soda is different to Bicarb!!!! Need to make sure you get Bicarb.

AC

By the way, this almost gave me a heart attack. I thought, "Oh my God, what have I been adding to my tank?" As the poster above states, this is not true for Arm and Hammer baking soda, at least here in the US.
 

Tug

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More is better.

abcemorse;32614 said:
I think I'd add more plants or let the cycle complete entirely before adding fish...just to be sure :)
Good idea abcemorse. So now I just need to add some somethin, somethins. I'll get my book.
 

Tug

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All tests prove is my deep need to validate stuff. V your the voice of reason. Keep it simple as simple is often best. My tank; still coming along slow. Two Oto cats keeping the algae at bay and the plants are showing some pearling.
My question is about the dKH,
VaughnH;32601 said:
I don't know what the amount of bicarbonate of soda needed is. "A smidgen?" But, if you have a KH test kit, that isn't too old, you can check the KH after you mix it, and verify it yourself. You don't need absolute accuracy. If it is between 3.5 and 4.5 that is fine for use in a drop checker.
The Co2 indicator made by Red Sea says, "not accurate with dKH below 4." So, after mixing my DIY 4 dKH solution and given the margin of error (half a smidgen is equal to .98g baking soda) I came up with the 4 dKH solution. The reagent they sell with the test is an orange color and I am showing a nice blue green from the indicator solution. But, can I be sure I am finding accurate readings? What is the reagent they are using? What happens if I make the indicator solution with 5 dKH?

Thanks V/E1
 

abcemorse

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As far as I know, as long as the solution is mixed using RO water, making a 5dKH solution will only change the color at which 30 ppm (or any given concentration for that matter) is indicated. For RO dKH solutions the pH/KH tables are reasonably accurate. I think people use 4dKH cuz at 30 ppm or so it's green to yellowish, and that's an easy color to see and differentiate, instead of, say dark blue vs light blue.
 

Tom Barr

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4 KH is the optima for the color differences based on our eyes, the CO2 is still the same, I suppose you could make the KH ref solution any number of KH units as long as there was a ph indicator solution that targets that new pH.

But Bromo blue and a KH of 4 works well.

What they said is correct(surprisingly, and rare it seems these days).

Regards,
Tom Barr
 

Tom Barr

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abcemorse;33672 said:

And I was being fair and somewhat nice:eek:

After reading Dupla and many other company sites about algae and excess nutrients, it's a bit ridiculous after the information has been out there for so long.
Many just mimic what everyone else says and goes with the dogma.

Regards,
Tom Barr
 

Tug

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slow and steady

The CO2 indicator turned nice and yellow. After taking CO2 from the hose off a yeast bottle, it took a day to settle back to a blue, blue/green. I doubt this yeast reactor will ever provide too much CO2. The support has been great! Go Tom! Thanks everyone.