Ammonia dropped suddenly - cycle ending?
- Thread starter Gomisan
- Start date
How about "KH is consumed via natural processes in all tanks" -- blanket statement. It's true and avoids a great big long techie explanation.
Roan
Roan
OK.. KH is consumed.. got it.
I am waiting on a Nitrite test kit to arrive from onine reseller, should be today.
All my current test kits are Hagen kits, water in a test tube jobs. I'm trying to be consistent with the lighting conditions when checking them too.
I'm a bit broke this fortnight, so wont be able to afford a fancy electronic pH tester just yet.
I'm still not convinced that carbonates and bicarbonates are naturally consumed in an aquarium. An acidic presence to counteract the PH raising capabilities of Kh would seem more likely. But I'll study on this more before I say anything else.
This is a good discussion where I actually learn more about aquaria.
This is a good discussion where I actually learn more about aquaria.
The short version goes something like this…
When Ammonia (NH3) gets turned into Nitrite (NO2) and then Nitrate (NO3), something has to have happened to the 3 hydrogens. One of them joins up with some oxygen and becomes an H2O molecule, the other two float around as free Hydrogen (H+): the 'H' in pH… pH is the measure of free Hydrogen ions. If your buffer is in good shape the free Hydrogens get snapped up. No buffer and they suddenly accumulate and cause a pH crash.
The long version is a bit more complicated but, for the curious folk, good to know.
And test kits make me crazy, always have.
:dive2:
When Ammonia (NH3) gets turned into Nitrite (NO2) and then Nitrate (NO3), something has to have happened to the 3 hydrogens. One of them joins up with some oxygen and becomes an H2O molecule, the other two float around as free Hydrogen (H+): the 'H' in pH… pH is the measure of free Hydrogen ions. If your buffer is in good shape the free Hydrogens get snapped up. No buffer and they suddenly accumulate and cause a pH crash.
The long version is a bit more complicated but, for the curious folk, good to know.
And test kits make me crazy, always have.
:dive2:
Snapped up by what? Do the H+ and H- form together into a neutral bond that does not affect pH?
From your link it says:
What do they mean by "exhausted"? Are they eradicated like above by combining with the H+ (bio-acidification) that is going on? Or are they in the minority to the acidifying ions? Therefore still existing freely like the originally are, there are just more H+ than H-.
And this:
What does that mean? It has removed the H- ions somehow? Where did they go?
Jeeze, I'm all confused now.
OK, this will probably be the last post in this thread, by me at least, as I think the question in the topic is answered and I can move on to other things.
Here's today's test results, and I'm pretty sure this all indicates the tank is cycled.
(Ohh and I've just picked up a couple of new test kits, Chlorine & Nitrite)
28/02/06
pH: 7.5
Ammonia: 0
KH: 40mg/L
Nitrite: 0
Nitrate: 5mg/L
Chlorine: 0
Thanks for all the useful info, advice, comments etc.
Here's today's test results, and I'm pretty sure this all indicates the tank is cycled.
(Ohh and I've just picked up a couple of new test kits, Chlorine & Nitrite)
28/02/06
pH: 7.5
Ammonia: 0
KH: 40mg/L
Nitrite: 0
Nitrate: 5mg/L
Chlorine: 0
Thanks for all the useful info, advice, comments etc.
Normal nitrification does eat KH. To be chemical about it: Two milliequivalents of bicarbonate are used* for every milliequivalent of ammonia oxidized to nitrate.
The levels of ammonia generated in a tank during fishy cycling do not as such depress the pH, it is bicarbonate utilization which lowers the pH.
There is something a bit peculiar about the whole test sequence. Are all of the fish still alive? Not very many Tetras will survive >3ppm ammonia. The nitrate increase and drop is not realistic either. The KH & pH drops are believable - there is very little natural buffer in that water.
Also, age some tap in a shallow bowl and test at 24 and 48 hours for pH.
*read as: exhauted/consumed counteracting bioacidification.
HTH
The levels of ammonia generated in a tank during fishy cycling do not as such depress the pH, it is bicarbonate utilization which lowers the pH.
There is something a bit peculiar about the whole test sequence. Are all of the fish still alive? Not very many Tetras will survive >3ppm ammonia. The nitrate increase and drop is not realistic either. The KH & pH drops are believable - there is very little natural buffer in that water.
Also, age some tap in a shallow bowl and test at 24 and 48 hours for pH.
*read as: exhauted/consumed counteracting bioacidification.
HTH
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All the fish are alive and seem quite happy, have done the entire time.
Since it's 'possible' for ammonia to exist in a non-toxic form, and still read high levels on the tests, I can't say what level the 'toxic' ammonia was, perhpas for some reason it never got high enough to trouble the fish.
The tank is now over 3 weeks old, all the original inhabitants are alive and well except for a neon or two who went missing in the fist couple of days. In fact, since they're such difficult bugegrs to count I may have never had more than 8 anyway!
Remember also those test results are just a sample from the past few days. I've graphed the results for the life of the tank so far and they look much like I was led to expect a cycling tank to look. The nitrate reading was an abnormality, but since it was just a once off it's quite possible it was a testing error.
Here's the rundown on the tank's life.
Days 1 - 9: Ammonia levels low, pH Steady at 8.0
Day 10: Ammonia starts to rise, Nitrates very low, pH steady
Day 11 to 16: Ammona moves into the danger zone, but frequent water changes and a steady pH mean it never actually get's into Hagen's 'Red Zone'
Day 17: Ammonia is still high, but a slight increase in Nitrate is detected
Day 18: pH starts to drop slighty, Nitrates rising
Day 19: pH drops to about 7.0, Ammonia slighly down, Nitrates at 50mg/L
Day 20: Theh odd day, Ammonia is almost all gone, Nitrates have skyrocketed to 110mg/L
Day 21 to present: pH has stabalised at 7.5, Ammonia & Nitrite are 0, Nitrate is about 5mg/L.
and that, my friends, has been the first 3 weeks of my tank's life.
Since it's 'possible' for ammonia to exist in a non-toxic form, and still read high levels on the tests, I can't say what level the 'toxic' ammonia was, perhpas for some reason it never got high enough to trouble the fish.
The tank is now over 3 weeks old, all the original inhabitants are alive and well except for a neon or two who went missing in the fist couple of days. In fact, since they're such difficult bugegrs to count I may have never had more than 8 anyway!
Remember also those test results are just a sample from the past few days. I've graphed the results for the life of the tank so far and they look much like I was led to expect a cycling tank to look. The nitrate reading was an abnormality, but since it was just a once off it's quite possible it was a testing error.
Here's the rundown on the tank's life.
Days 1 - 9: Ammonia levels low, pH Steady at 8.0
Day 10: Ammonia starts to rise, Nitrates very low, pH steady
Day 11 to 16: Ammona moves into the danger zone, but frequent water changes and a steady pH mean it never actually get's into Hagen's 'Red Zone'
Day 17: Ammonia is still high, but a slight increase in Nitrate is detected
Day 18: pH starts to drop slighty, Nitrates rising
Day 19: pH drops to about 7.0, Ammonia slighly down, Nitrates at 50mg/L
Day 20: Theh odd day, Ammonia is almost all gone, Nitrates have skyrocketed to 110mg/L
Day 21 to present: pH has stabalised at 7.5, Ammonia & Nitrite are 0, Nitrate is about 5mg/L.
and that, my friends, has been the first 3 weeks of my tank's life.
