What does this tell me?

JoshP12

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Hi all,

I was inspired on an idea when I read a thread about the 2dKH drop checker.

So I whipped one up and set up side by side with my 4KH.

1592773912302.jpeg

The one on the right is the 2Kh. You can see a heavier yellow in it.
I had my wife do the readings (better eyes , ha) with the pH chart for me and she said the
2Kh = 6.2
4kh= 6.4

Read from in water.

So, using the ph kh chart which bears its own in accuracies, am I somewhere in between 37 and 47 ppm?

Ultimately, and I think the point, is can you rule out co2 as the root of issues in a tank at this “level”.

Josh
 

Zeus.

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But how stable is the level!

The key to injecting CO2 is it needs to be stable from lights on till CO2 off.

The change in colour only indicates a [CO2] in the past, a pH profile along with a DC colour change tells us much more ;)
 

JoshP12

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But how stable is the level!

The key to injecting CO2 is it needs to be stable from lights on till CO2 off.

The change in colour only indicates a [CO2] in the past, a pH profile along with a DC colour change tells us much more ;)
If it is like this from lights on, what does it tell us?

Josh
 

Zeus.

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Well the DC colour change is about two hours behind the actual [CO2]/pH. So the Dc colour at lights on will only give you the [CO2] only if your injection 24/7.

If you do a pH profile using a pH pen or pH papers, taking the pH every 30mins from CO2 on till CO2 off, will will get a graph of pH over time, we are after the pH being stable from lights on till CO2 off.

Once stable from lights on till CO2 off, then the DC colour 2 hours after lights on tells us the [CO2] from lights on till CO2 off.

Get the pH/[CO2] stable by adjusting the injection rate/BPS once stable at the [CO2] you are after, just time how long it takes to get the pH drop, if it takes 2hrs its 2hrs , if it take 3hrs 20mins its 3hrs 20mins - do not abust your injection rate/BPS to try and speed it up as it only messes up your stable pH/[CO2]


The only way to speed up the pH drop without it affecting your stable [CO2]/pH is with duel injection and duel solenoids and duel timers, which is what I do and it makes life much easier, ignoring the cost ;)
 

JoshP12

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Thanks @Zeus. !

My pH is stable from lights on - I have a constant probe taking measurements all the time (so I can just peek and compare to the previous few days as it graphs it - photo attached ... the one blip down was an adjustment I made in BPS and the major increase was a water change).

But I am curious if sandwiching my DC, giving an upper and lower bound for the co2 approximation, can give me a better idea on my actual co2 amount.

I currently don’t have any major issues in plant growth, but I want to see what my conditions that are giving rise to the growth that I am seeing are.

I’d also like to know if I can rule out co2 at my current lighting intensity and photoperiod, so I can go ahead and systematically adjust other parameters and observe 🤓 (of course plant density will change the demand, but knowing that is enough - I think).

If problem do arise, and co2 remains constant and at my approximated ppm, then I can say it must be ... etc.

Josh
 

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jaypeecee

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Hi @JoshP12
If it is like this from lights on, what does it tell us?
Forgive me as my remaining three brain cells are on a 'go slow' at the moment! But, it seems to me that:

1 Your CO2 level is possibly in excess of the 'safe' level of 30 ppm before lights switch ON. No prizes for me spotting that!

2 How could there be such a significant difference between the two readings (37 vs 47 ppm)?

May I ask how you measured KH? It's necessary to get KH accurate for DC fluid. I make up my KH fluids to +/- 0.1dKH using either the Salifert KH/Alkalinity Test Kit or Tropic Marin KH/Alk Pro Test Kit. It's not possible to use something like the API KH Test Kit as the best you'll get is +/- 0.5dKH.

Now, I've got just one brain cell left. And that one's broken!

JPC
 

JoshP12

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Hi @JoshP12


Forgive me as my remaining three brain cells are on a 'go slow' at the moment! But, it seems to me that:

1 Your CO2 level is possibly in excess of the 'safe' level of 30 ppm before lights switch ON. No prizes for me spotting that!

2 How could there be such a significant difference between the two readings (37 vs 47 ppm)?

May I ask how you measured KH? It's necessary to get KH accurate for DC fluid. I make up my KH fluids to +/- 0.1dKH using either the Salifert KH/Alkalinity Test Kit or Tropic Marin KH/Alk Pro Test Kit. It's not possible to use something like the API KH Test Kit as the best you'll get is +/- 0.5dKH.

Now, I've got just one brain cell left. And that one's broken!

JPC
Hey JPC! For my solution, I used baking soda + distilled water with Rotala Butterfly for measurement, then I checked with my Hagen test kit; it tested out at 70 ppm as a tingey yellow, if I pushed it once more, then the titration would probably be complete and peg me at 80 ppm ... so it may be like 75 ish ppm ... 4 ish dKH ... but I mean it has to be close enough.

I just linked this for easy reference:
1592844790741.png


First off, my bromothymol blue solution only has colors going up by .2 ... that means that when I asked my wife to look for me, she will pinpoint an interval of .2.

So 6.4 at 4kh is giving me the 47
6.2 at the 2 kh is giving me the 37.

It is possible that I am actually at 6.5 on the 4kh giving me 37 OR 6.1 on the 2KH giving me 47 - not sure - and I don't think this pH indicator is that good.

My pH drop is about 1.2 from off-gassed as well. So I am thinking with this sandwich (upper and lower bound), I am at about 40ish - which seems to be nice. But I just wanted some seasoned opinions :).

Josh
 

jaypeecee

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Hi @JoshP12
So I am thinking with this sandwich (upper and lower bound), I am at about 40ish - which seems to be nice. But I just wanted some seasoned opinions :).
I'm not sure that 40 ppm CO2 is 'nice'. On the contrary, that's obviously higher than the oft-suggested maximum of 30 ppm. As with a lot of toxicity figures, there is an acute toxicity figure and a chronic toxicity figure. These terms are self-explanatory. Excess CO2 can cause a condition in fish known as nephrocalcinosis. For further information, please take a look at the following. I hope you're not squeamish!

https://fishhistopathology.com/home/2019/08/22/nephrocalcinosis-in-fish-gross-pathology/

JPC
 

JoshP12

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That internal surface of one of the drop checkers was contaminated with CaCO3 or any other buffer?
I don't think it was - I used distilled water. I rinsed one of them with tap water - and my tap water has 10 ppm of KH, so it is quite soft. One of the DC is 2KH the other is 4KH though.

Josh
 

hypnogogia

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I think it's significant that the latest DC from JBL has 20 ppm as the optimum CO2. Take a look at this:
I have often thought that the term ‘nature aquarium’ in the context of 30ppm co2 is an oxymoron. Interestingly Amano (who coined the term nature aquarium AFAIK) used much less co2. I wonder if this contradiction is in itself a good topic of discussion for UKAPS.
 

JoshP12

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I have often thought that the term ‘nature aquarium’ in the context of 30ppm co2 is an oxymoron. Interestingly Amano (who coined the term nature aquarium AFAIK) used much less co2. I wonder if this contradiction is in itself a good topic of discussion for UKAPS.
Edit: I deleted what I wrote as I think that is a different discussion - hah! But I am intrigued on this one.
 

JoshP12

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I have often thought that the term ‘nature aquarium’ in the context of 30ppm co2 is an oxymoron. Interestingly Amano (who coined the term nature aquarium AFAIK) used much less co2. I wonder if this contradiction is in itself a good topic of discussion for UKAPS.
Does anyone know how Amano actually injected CO2?

The only structured approach that I have read are as follows:
1) pH profile with lowest point at lights on
2) DC green at lights on, lime green in 2 hours.

... then the rest becomes cryptic:
1) Match your light to CO2
Or it is just not talked about - or I don't know where to find it.

... then all the way on the end I hear "you turn it on, then watch your tank, then turn it up some more, then continue this until you feel it is good" <-- its so simple that it is genius ... but.

The pH profile + stable worked for me - I am extremely happy with my tank (thanks to UKAPS); however, I would like to know the other strategies ... for learning.

Josh
 

Big G

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Does anyone know how Amano actually injected CO2?



Josh
Not sure if this helps but in book one of 'Nature Aquarium World' by Takashi Amano , next to each photo, he lists many parameters of that given 'scape including but not limited to co2 ppm. Having a quick flick through the book again, I'm not seeing anything over 20ppm or, as he prefers, mg/l. As far as the method, 'IC Controller' (internal canister?) is often stated next to 'co2 supply'.The book is a total keeper by the way, almost canonical, it might be argued.

Hope this helps

BG
 

rebel

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I'm not seeing anything over 20ppm or, as he prefers, mg/l.
Those old scapes used quite low light as measured by Tom Barr. I don't think he measured above 50 PPFD at the sub.
 
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JoshP12

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Not sure if this helps but in book one of 'Nature Aquarium World' by Takashi Amano , next to each photo, he lists many parameters of that given 'scape including but not limited to co2 ppm. Having a quick flick through the book again, I'm not seeing anything over 20ppm or, as he prefers, mg/l. As far as the method, 'IC Controller' (internal canister?) is often stated next to 'co2 supply'.The book is a total keeper by the way, almost canonical, it might be argued.

Hope this helps

BG
Thank you for this information. - I need to get a hold of this book :)
 

JoshP12

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Those old scapes used quite low light as measured by Tom Barr. I don't think he measured above 50 PPFD at the sub.
Hmmm ... isn't it suggested to use "lower light" anyways as opposed to high light? We only need to get above LCP and a bit more. Meanwhile, I've never read to use "moderate" CO2.

Josh
 

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