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Basic question on DC

Try placing a white card against the DC in tank (from the outside unless you happen across plastic white card;))

But you’re right, present trend in LED lighting can impact how colors looks (compared to T5 lighting days when CRI was considered very important)

(Should I admit to having never used a drop checker or pH profile)
 
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Hi @JoshP12
Do you read a Drop checker in the tank or out of the tank?

The simple answer is that I 'read' my DC whilst it's in the tank. It would be very inconvenient to have to remove a conventional DC from the tank water in order to read it. But, I understand your concern about the colour shift. I don't rely exclusively on my DC for CO2 measurements. It has too many shortcomings in my view - very slow to respond to changes in CO2 concentration, colour determination open to interpretation and others. I use a different approach that makes use of a pH meter. If you or anyone else is interested, just PM me and I'll gladly provide more details.

JPC
 
Hi @hypnogogia
I believe there is a brand of DC where the fluid bubble sits outside of the tank.

I think you're right. But I suspect that would make it slower to respond to changes in CO2 concentration. The length of the airspace through which the CO2 would need to diffuse before reaching the water/KH buffer/bromothymol blue must surely be longer than the conventional DC - or maybe not. I would need to see a picture of it.

JPC
 
I found the DP the least useful tool to monitor CO2 distribution. First, it is not easy to read the color. Second, there is a time lag in the response. Third, it doesn’t account for location variability.

I found it easier and more informative to map pH profiles and compare with degassed pH using the kH-pH table to estimate CO2 distribution with time and space.. A pH pen is useful in quick pH measurement. Over time, I rarely check pH but rely on the bubble counts to estimate the adequacy of CO2. At the end, no matter what you do is not a direct measurement of CO2 but a proxy of what you intend to measure.
 
I totally agree @tiger15. There are errors with many of the tools we use and most everything is a proxy for a general idea - with the livestock and plants as the true tell all - which lead me to <here>

I use a pH probe in the center of the tank; I used a drop checker on top and bottom; I used drop checkers on either side. For the first time <things are going well> ... yipee!

Here would be a 5 day pH profile with a water change and smooth transitions up and down.
1592830508422.png
PS the time stamp isn't accurate LOL. :eek:🤣
Today at lights on my dual drop checkers read like I mentioned in <this post> as I try to zero in on a better proxy as I too struggle with the color identification from a single inaccurate DC. Bromothymol is narrow range but it isn't so narrow when you are trying to troubleshoot potential issues in the tank. Certainly, this indicates to me that I can shave time off of my 4 hour before lights on ... and I will shave it off slowly.

The fear of reducing the CO2 and dropping into the BBA zone (15-20 ppm) ... although I think that zone can be completely mitigated with the use of a non-EI dosing and strategy whilst reducing the CO2 demand by limiting other primary nutrients. But I dose EI - my hopes and I want to see what happens is that if I can be certain of my CO2 conc (within reason of course) with the dual proxies (and reading it properly, albeit consistency in my reading is (in-tank or out of tank) is more important), then I can lean out my dosing regime and see what actually happens - in search of the true balance of the tank. Alternatively, maybe I can play with the lights and get more light ... Why? Who knows! Slightly crazy perhaps 🤣.

It is very easy to say that you don't need so much light when you have harnessed the ability to use high light.

My next post will probably be in fertilizations where I am going to start thinking about nutrients differently - but that's for another day.

Josh
 
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