Experiment: Extreme cycle

[Caliban07]

Yes check em out. Only downside is the ads.

I was also recommended a book called Perry's chemical engineering by a chemical engineer who came in the hospital. It's £70 and I'm just not sure what level this book is aimed at.

Apparently though Chem eng is different to actual chemistry. A LOT more math. Particularly calculus. I don't have a problem with math though. As long as there's a method I find it easy.

 

[threnjen]

Yes check em out. Only downside is the ads.

I was also recommended a book called Perry's chemical engineering by a chemical engineer who came in the hospital. It's £70 and I'm just not sure what level this book is aimed at.

Apparently though Chem eng is different to actual chemistry. A LOT more math. Particularly calculus. I don't have a problem with math though. As long as there's a method I find it easy.

Calculus noooo /cringe
Math is not my strongest suit. I suppose I would have to improve there. It's not that I can't do it, I always took the hardest courses available to me in high school, but I didn't do much math at university because it wasn't really part of my major.

 

[Supergummy]

I keep having to read the whole entire thread over again, still try to process it. Lol

 

[threnjen]

edit: figured it out

Sent from my SGH-M919 using Aquarium Advice mobile app

 

[threnjen]

Here are today's test results. Some really interesting surprises.

a) TDS dropped from around 100 the entire time, to 83
b) pH dropped to 7.19 from yesterday's 7.29 and the earlier 7.37. So basically, pH started dropping as soon as nitrites appeared
c) kH 6 still today
d) Phosphates holding from yesterday as far as I can tell
e) Ammonia is now close to the 2ppm solution, so I am pegging it at 10ppm (remember I do the tank in a 25% reduction so it is readable)
f) NitrItes I am estimating at 8ppm. I kept yesterday's tests as they stay "good" and today's 25% reduction was right in between yesterday's 50% and 100% which I had estimated around 1.5 and 3, so we'll call it around 8ppm.
g) WE HAVE NITRATES. What???!! This is the first day I tested as I was certainly not expecting them yet! Whoops!! I was really in shock and I ran the test again as well as a tap water test to confirm 0 in tap. They are in the 5-10 range! I can't believe it.


I've realized that reference solutions would be really relevant right now for these estimates I am trying to make Next cycle I will have full reference solutions for all three and it will be more exact.

 

[threnjen]

Did the math for making the nitrite and nitrate solutions... just need to find the time to do this. So, so busy this week. The cycle experiment and my real life are not coordinating very well

 

[Caliban07]

I remember saying we still have a few days to see nitrites appear and that was a few days ago so I don't think I'm surprised.

Would definitely expect ph to drop now as there are 2 bacteria going full throttle now although nitrites may take a while to come down.

 

[threnjen]

Today is a very important day. CRAZY things have happened. It's particularly important because NOW is the moment of "will high nitrites stall the cycle?" From here out, I have a lot to prove. I'm not sure why I am placing so much importance on this working out

a) pH CRASH! Dropped to 6.23
b) kH has dropped to 2.5 (from 6, 24 hours ago)
c) TDS holding at 83 like yesterday
d) PO3 holding at 5
e) Ammonia dropped drastically. It is now 4ppm (down from 12 yesterday). This means that tomorrow, ammonia will be gone.
f) Nitrites. This one is TOUGH. I even did a 1/10th reduction and it is STILL pretty dark purple. It is a BIT lighter than yesterday's 4ppm guesstimate vial. I'm going to make a guess largely on that and call it 30. The math is not necessarily lining up though, because ammonia converts to nitrites and nitrates at a specific rate, and 30 seems high. The problem is that I can't really accurately read either nitrites or nitrates. See the next step for more thoughts and for my final estimates.
g) NitrAtes I am guessing now at 20 as the vial has acquired a reddish tone. I did a 50% reduction and it had the light orange of 10ppm. BUT it COULD that the reduction was more in between 5 and 10... placing current nitrates more at 10-15. It's SO HARD.

For NitrAtes to be 15, that would mean that 4ppm ammonia has been processed through to nitrAtes. If I dosed accurately to 16ppm to start, this would leave only 8ppm ammonia, which would only be 21.6 nitrites. If I overdosed ammonia to 17ppm on accident to start, there could be as much as 24.3. The nitrItes vial is very dark. I really think it's too dark to be only 21.6. I also ran a test with the seachem nitrite test and it instantly flew off the chart (which tops off at 25)

SO. For mathematics sake, and assuming that no ammonia or nitrites have magically entered the system, I will go with the following:
NH3/4 - 4ppm
NO2 - 24.3ppm
NO3 - 15ppm

I think these are fair and reasonable estimates.

Next time I run this experiment (and there WILL be a next time) I will carefully have several control reference solutions in order to avoid the issues of guesstimation that I am having this time. This time we might have to settle more for the process than for perfect accuracy. In the future I will be able to learn better from my mistakes this time.

Fun fact... I did 13 test vials today. LOL.

I call today very important because there is 24 nitrites in the system and another 10.8 will shortly be added when the remainder of the ammonia is processed. I will NOT be doing a water change.

Edit to add: Added 2tsp baking soda to raise pH to 7.5

 

[Delapool]

Wow - that's really interesting on the ph crash. Makes sense but I had always assumed it would be a slow decline.

 

[Caliban07]

Yeh sounds very interesting. How much has ph dropped in total so far?

 

[threnjen]

It started off the chart but I worry there was some error because then it was suddenly 7.4 for a long time.

I remember when cycling a test bucket a few months ago, the pH crashed just like this. Literally overnight. I was actually expecting the crash, I just wasn't sure where it would occur. It will probably drop quite a bit tomorrow but not crash all the way since there is only 4ppm ammonia left to eat right now.

 

[Caliban07]

Just think, if we knew the dkh level at which kh stopped buffering acid we could have used math to calculate exactly how much baking soda you would have needed at the beginning to protect against ph swings. If we know that the alkalinity used to get 1ppm ammonia ---->nitrate is 7.14. I think that was to get it to nitrate? Or was in just to nitrite and does this take in to consideration the acid produced as well as alkalinity used?

Would have been a serious math exercise though

 

[Delapool]

Do you think the crash is normal or 'extreme cycling'? I guess I've always had ph slide gradually but it would have been buffered a bit by water changes. If it can crash like that I'm a bit worried as I was thinking you could kind of start with an ammonia level and come back 4 weeks later to a cycled tank - rethinking this

 

[Caliban07]

I think fishless cycling is in a lot more danger for a ph crash as these levels are pretty high.

Maybe 1 dose of 4ppm then leave it would be enough?

 

[Rare]

I think fishless cycling is in a lot more danger for a ph crash as these levels are pretty high.

Maybe 1 dose of 4ppm then leave it would be enough?

I can't recall all the details but I added 4ppm & pH went below 7.0 from a ph of 8.2 to start. When i did my other tanks i added sodium bicarbonate not to have the same pH dip.

 

[Rare]

Scratch that, it was back2back once ammonia was at 0

 

[Caliban07]

Scratch that, it was back2back once ammonia was at 0

What do you mean back to back? You kept topping up ammonia?

 

[Rare]

When I first started the fishless cycle & ammonia finally was processed to 0, I dosed it back to 4ppm. Not back to back per say, but what i meant i wasnt one dose of 4ppm ammonia for the cycle.

 

[threnjen]

I don't think one dose of 4ppm ammonia would be enough to cycle a tank to any appreciable level. It would probably only cycle it to .5 or something so you will just have to dose more ammonia later.

Caliban - that would be some very helpful math. BUT you also don't want the pH to start off too HIGH. I think there has to be some dosing of baking soda in there. It's really not a big deal though. I think this method would require LESS testing and dosing.

Delapool - I'm not sure why the baking soda specifically sounds like a dealbreaker to you - the only thing you need to "redose" in this whole experiment is sodium bicarbonate, and only once. How is that so much worse than dosing ammonia all the time?


I want to reduce a lot of the "thinking". Dosing back up to 4ppm all the time. Testing ammonia every day and calculating how much more to add to dose it back up.
What is wrong with just dosing it and basically forgetting it? Sure, you have to test ammonia and pH every couple days. But the cycle doesn't FAIL if there is a pH crash and you are a day late noticing. Nitrification picks right back up when you bolster the pH back up.

 

[Caliban07]

I don't think one dose of 4ppm ammonia would be enough to cycle a tank to any appreciable level. It would probably only cycle it to .5 or something so you will just have to dose more ammonia later.

Caliban - that would be some very helpful math. BUT you also don't want the pH to start off too HIGH. I think there has to be some dosing of baking soda in there. It's really not a big deal though. I think this method would require LESS testing and dosing.

Delapool - I'm not sure why the baking soda specifically sounds like a dealbreaker to you - the only thing you need to "redose" in this whole experiment is sodium bicarbonate, and only once. How is that so much worse than dosing ammonia all the time?


I want to reduce a lot of the "thinking". Dosing back up to 4ppm all the time. Testing ammonia every day and calculating how much more to add to dose it back up.
What is wrong with just dosing it and basically forgetting it? Sure, you have to test ammonia and pH every couple days. But the cycle doesn't FAIL if there is a pH crash and you are a day late noticing. Nitrification picks right back up when you bolster the pH back up.

How come 4ppm wouldn't be enough? I'm thinking the bacteria would grow to a level to tackle this and just go for dormant again.

No I know I wasn't specifically saying to use it for the experiment. It was just something I was pondering on. More specifically. At what point does dkh stop buffering ph? There's obviously going to be variables but surely it could bd estimated or calculated.