A New Optimum Dissolved CO2 Concentration?

[jaypeecee]

Hi Folks,

It would appear that JBL have decided on a new optimum CO2 level in users' tanks. Instead of the 30 mg/l figure, which has been 'the norm' for a good many years, JBL seem to be rolling out their latest drop checker (DC) test sets with a new optimum of 20 mg/l. See below:

https://www.jbl.de/en/products/detail/8688/jbl-proaquatest-co2-ph-permanent

Note also that the figure below the optimum is 12 mg/l and the figure above is 50 mg/l. I haven't yet fathomed out what combination of KH and reagent (e.g. bromothymol blue) JBL are using.

JPC

 

[Heavenly]

I purchased this to run it alongside my standard glass drop checker from CO2Art.
I’ve read the literature and it appears they are looking at a generalisation for everyone Now for safety levels so stating 20-25 for fish keepers and 30 for specialists aquascapers.
I’ve got my drop to 1 PH today, 7.5 gassed out to 6.56 in tank and drop checker nice lime green.
However the JBL drop checker after 3 hours from lights on is not showing anywhere near 20 mg/L. :/

 

[Zeus.]

drop checker nice lime green.
However the JBL drop checker after 3 hours from lights

sometime not right there
Are they the same solution , don't think they are obviously.
I would change the solution over to different DC if you have two solutions

 

[jaypeecee]

Hi @Heavenly

OK, I have a few comments.

As JBL is possibly the biggest and most influential supplier of CO2-related equipment and other products in Europe, their move to an optimum CO2 of 20 ppm is significant. There can't be one figure for fish keepers and another for aquascapers as they both, normally, keep fish. And, it's the fish plus other aquarium inhabitants that dictate the safe upper limit for dissolved CO2 concentration. Although the 1pH drop is promoted widely, I (and others) don't support this. That's because a 1pH drop corresponds to a tenfold increase in CO2 concentration. So, if the starting CO2 concentration (before CO2 injection) is, say, 4 ppm, this figure will increase to 40 ppm. More discussion here:

https://www.ukaps.org/forum/threads/why-advise-a-1ph-drop.58798/

However the JBL drop checker after 3 hours from lights on is not showing anywhere near 20 mg/L

That doesn't bode well for JBL, does it?

JPC

 

[Heavenly]

Zeus - they possibly have different solutions in, however If my usual drop check goes green on a 1 PH drop I would expect whatever solution is in the JBL to have reacted and to have changed green especially if it’s only marked as a 20 mg/L drop not 30...my usual was lime green at lights on, the JBL wasn’t anywhere near green 3 hours in..
What I will say being only 6 months Into planted tanks, and still learning, on this drop all my fish and shrimp have been fine, but my 2 rainbow neons suffered, laboured and struggled at the surface so maybe a 0.8 drop down to 6.7 not 6,5 would be better. The fact they have gone now means I am still doing a 1 PH drop as my SAE, Otto’s, Rummynose and Green neons all seem fine...