Experiment: Extreme cycle

[threnjen]

Well 2 mols of acidity are produced for every 1 mole of ammonia oxidized. I do not know how to convert that into usable information though. That's just the chem reaction of oxidation.

 

[Caliban07]

Except that you can have pH higher than "stall level" and be out of kH, can't you?
You can have pH 7.2 water that has 0 kH, or is that incorrect?

I guess you could. In a normally running aquarium kh would be replenished with water changes and alkalinity used would not be enough to affect fish. If someone was running an aquarium on 0dkh then I'm sure ph would start to fall pretty rapidly.

In a fishless cycle I don't think ph of 7.2 would hold very long without a buffer.

If your tap is 7.2 and your dkh was 0 then that is what the water has settled at with its chemical makeup. Since there is no extra acids added to the fray then it can hold pretty stable.

This is how I understand it anyway I could be wrong.

 

[Caliban07]

Well 2 mols of acidity are produced for every 1 mole of ammonia oxidized. I do not know how to convert that into usable information though. That's just the chem reaction of oxidation.

This is good. I'm just thinking if the end result would be able to tell is anything. Even if we knew how much acids was produced from 16ppm ammonia conversion, how would we tie that in without knowing the exact hydrogen ion ratio?

I think the next experiment is to see if this initial bicarb dose alters ph above 8.4 and whether it holds steady throughout the cycle.

 

[threnjen]

But how can any nitrification occur at all with 0 dkh?

If I have a tank with pH 7.2 and 0kH, I would expect that nothing at all happens with nitrification. There is no alkalinity available for the bacteria to eat. Therefore nitrification would halt.

yes/no? Maybe I am just still not grasping this.

 

[Caliban07]

Yes I see what you are saying now. It does make sense.

Look at your posts on the first page when ph starts to drop significantly. Why has kh not budged before ph starts to drop?

 

[Caliban07]

How does ph up work. If it doesn't add carbonates then maybe you could use it as an experiment?

 

[Caliban07]

You could strip the water of carbonates then add ph up to get a desired level then see if you can start a cycle with 0 alkalinity?

 

[Caliban07]

Or better still don't add any baking soda at the start of the next cycle. Since your tap water has very low dkh and an averagish ph you could does your 16ppm ammonia and just leave it be. IF it stalls and dkh depletes down to 0 and you add baking soda and it Kick starts again then you have nailed it and you can have the Nobel prize.

The penny has dropped now I do see what you are saying.

 

[Caliban07]

Btw apparently sodium bicarbonate will try to keep the ph level at 8.4 (we know this already) this is where it gets tricky.

If the ph is say 9.4 then the bicarbonates will lend hydrogen ions back to the water to reduce ph to whatever the buffers preferable ph level is. From a baking soda point if view this is 8.4.

 

[threnjen]

Yes I see what you are saying now. It does make sense.

Look at your posts on the first page when ph starts to drop significantly. Why has kh not budged before ph starts to drop?

I think there was something else amiss there. Why did I get a few days of bright fuschia tests? Maybe I forgot to shake the test solution. I don't know... I have a problem with those results. Why did pH abruptly drop out of nowhere?? It really makes no sense.
Just another note for the next round to take notice of.

 

[threnjen]

How does ph up work. If it doesn't add carbonates then maybe you could use it as an experiment?

No clue, what is in it? I think that "pH down" is phosphoric acid (which would solve at least one person's cycling problems that I can think of in newbie area) but I don't know what pH up is. Probably because there are so many other easy ways to raise pH.

 

[threnjen]

Or better still don't add any baking soda at the start of the next cycle. Since your tap water has very low dkh and an averagish ph you could does your 16ppm ammonia and just leave it be. IF it stalls and dkh depletes down to 0 and you add baking soda and it Kick starts again then you have nailed it and you can have the Nobel prize.

The penny has dropped now I do see what you are saying.

I think my pH is not high enough to start with, I am pretty certain I will have the pH crash along with everything else. Both of the times I have cycled before I had a pH crash. The first one was on my main tank and its how I found this forum, the other site didn't teach about pH crash at all.

I'm trying to remember the details of my 2 fishless cyles...
The big one was stalled a long time, that was before I knew about kH though. I eventually tested the pH and that was how I knew.
Then a couple months back I cycled a bucket and it had a crash, but I did not use kH then either.

I have an idea that will refine your idea. I can use gH booster to raise the pH without raising the kH. Seachem Equilibrium. It's possible to have high pH without a high kH if the pH is from calcium and magnesium. So if I start a cycle with pH 8, it could stall before the pH crashes.

My theory may not hold water overall, as it's difficult (although possible) to imagine a situation where the kH could deplete without the pH really showing this significantly. But I hypothesize that it's POSSIBLE

 

[threnjen]

Btw apparently sodium bicarbonate will try to keep the ph level at 8.4 (we know this already) this is where it gets tricky.

If the ph is say 9.4 then the bicarbonates will lend hydrogen ions back to the water to reduce ph to whatever the buffers preferable ph level is. From a baking soda point if view this is 8.4.

But it's not true 8.4?
I read that you can't "overdose" it since it will stop at 8.4. Does the problem only apply if your starting pH is higher than 8.4?

I mean I guess in good news, that is a really rare pH to be so high

 

[threnjen]

... Have you guys noticed you can put in a custom title instead of "Aquarium Advice _____"
Join the team Membership is open to all who opt to include themselves!

 

[threnjen]

Anyone else have bandwidth/supplies to try a "Set it and forget it"? Even if I can do it a dozen times, it's only applicable to my own water. You don't have to test like a spaz like I do, just see if it works. Can do it in a bucket!
You need: filter, heater, ammonia, baking soda, fish flakes (or if you use dry ferts, your phosphate mix)

 

[Caliban07]

But it's not true 8.4?
I read that you can't "overdose" it since it will stop at 8.4. Does the problem only apply if your starting pH is higher than 8.4?

I mean I guess in good news, that is a really rare pH to be so high

"as the pH tries to rise, Carbonic Acid will first dissociate, into Bicarbonate plus one H+ ion, or further into Carbonate plus two H+ ions. (Dissociate is just a Chemist’s way of saying, split up). As it dissociates (towards the right), it releases, first one H+ ion, then a second one. Since pH is the ratio between H+ and OH- ions, what is happening here is that as the pH tries to rise, more and more H+ ions are released into the water and reduce the value of the pH back to what it was before it began to rise"

"Reading from right to left, if the pH begins to fall, the reverse happens. Carbonate will grab hold of, first one, H+ ion then a second one, as it changes to Bicarbonate then to Carbonic Acid. This reduces the number of H+ ions and so will increase the value of the pH back to what it was before it began to fall.

Chemicals that try to keep the pH at a particular value are called “buffers”. These are stroppy little compounds. They like to get their own way. There are a great many of them and each has a preference for a particular pH. When placed in water, they immediately change the pH of that water until it is exactly where they want it. Not only that, but they will selfishly try to keep it there. Sodium Bicarbonate is one such chemical. When it is dissolved in water, it immediately tries to adjust the pH by releasing or absorbing H+ ions. If you remember that the value of pH is “something to do with the balance between H+ ions and OH- ions”, it is obvious that anything that either releases H+ ions or mops them up, can alter the pH to it’s preferred value. When the pH reaches 8.4, Sodium Bicarbonate stops releasing H+ ions or absorbing any, so Sodium Bicarbonate is called a buffer with a preferred value of 8.4"

That's what my reference says

 

[Caliban07]

Anyone else have bandwidth/supplies to try a "Set it and forget it"? Even if I can do it a dozen times, it's only applicable to my own water. You don't have to test like a spaz like I do, just see if it works. Can do it in a bucket!
You need: filter, heater, ammonia, baking soda, fish flakes (or if you use dry ferts, your phosphate mix)

I do have a 6 gallon I could cycle. You might have to send me some ace ammonia or whatever it's called and I'll give you the money?

 

[Caliban07]

"Below 8.4, Bicarbonate absorbs H+ ions and the equation moves to the left, making the water more alkaline. This continues until the pH reaches 8.4 when the process stops"

"Above 8.4, Bicarbonate releases H+ ions and the equation moves to the right, making the water more acidic. This continues until the pH is 8.4 when the process stops."

I forgot to add this bit on to that post before

 

[threnjen]

I do have a 6 gallon I could cycle. You might have to send me some ace ammonia or whatever it's called and I'll give you the money?

Yeah I could do that. It might be too expensive though to be worth it (even if we split the shipping). I wonder what the smallest amount I could send would be to keep the weight down. I'll think it over tomorrow what kind of container I could put it in.

 

[threnjen]

"Below 8.4, Bicarbonate absorbs H+ ions and the equation moves to the left, making the water more alkaline. This continues until the pH reaches 8.4 when the process stops"

"Above 8.4, Bicarbonate releases H+ ions and the equation moves to the right, making the water more acidic. This continues until the pH is 8.4 when the process stops."

I forgot to add this bit on to that post before

I think I get it now, that site had an excellent explanation. Helpful that it holds pH at such a nice nitrification point