I've never used a drop checker, but have you guys seen those "double check" Cal Aqua ones? Instead of using one as a reference, if one used different KH solutions on each one should be able to a better idea of how much CO2 they have with minimum/maximum limits. (Say, I have one at the standard 4dKH solution and the second to say "too low", if say, under 50ppm CO2.)
Drop Checkers and Target CO2
- Thread starter czcz
- Start date
The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
I think it sounds like a great idea czcz. Would certainly add a good bit of information... certainly more accurate than using a single. Unfortunately, I don't have access to a scale sensitive enough to make 4dKH solution (or any specific dKH solution for that matter. I will keep this method in mind though for when I do happen upon the ability to get my hands on some specific dKH solution in the future.
Is anybody else up for this? I'll weigh some out if you guys want... should I be worried about sending lots of little bags of white powder all throughout the country through the mails? .... ....
Its easy if you add one more step into your dilutions. If you dilute the baking soda first in such a way that say 5mLs of your solution into a gallon of water is 1dKH, then just pull from that gallon of water for the drop checker, it will be easy without a scale. I am not up for asking the google at the moment or searching through the sticky links, but I am sure someone has posted tsp and TBL weights of baking soda. If they haven't, I am happy to weigh some samples after the holidays if anyone is interested, or post the ratio/how to mix in easy steps for a reasonable container size. Like 1L or 500mL?
Its easy if you add one more step into your dilutions. If you dilute the baking soda first in such a way that say 5mLs of your solution into a gallon of water is 1dKH, then just pull from that gallon of water for the drop checker, it will be easy without a scale. I am not up for asking the google at the moment or searching through the sticky links, but I am sure someone has posted tsp and TBL weights of baking soda. If they haven't, I am happy to weigh some samples after the holidays if anyone is interested, or post the ratio/how to mix in easy steps for a reasonable container size. Like 1L or 500mL?
I would be down to give it a try. Do you have a link to the "double" drop checkers?
Yeah -- CAL AQUA LABS Double Drop Checker | Green Leaf Aquariums I have not ordered from these guys yet but am so impressed by their owner's openness and contributions to our hobby I am certain they're getting at least my next fert order.
Floated the idea above past a friend who likes it too, but (though have not looked seriously) I've not found what ranges or a formula to calculate what the low and upper thresholds for the color is. I'll build a little web calc for it where you can stick in a target CO2 and it will spit out how much baking soda (mg and tsp) to start the dilution with, derived from the current 4dKH for 30ppm CO2 colors we know of. With all the great calcs online today maybe it will still fill some niche. I need one that will do anything from mass percentage anyway (our old fishless cycle/ammonia/from solutions calc). Will post
Floated the idea above past a friend who likes it too, but (though have not looked seriously) I've not found what ranges or a formula to calculate what the low and upper thresholds for the color is. I'll build a little web calc for it where you can stick in a target CO2 and it will spit out how much baking soda (mg and tsp) to start the dilution with, derived from the current 4dKH for 30ppm CO2 colors we know of. With all the great calcs online today maybe it will still fill some niche. I need one that will do anything from mass percentage anyway (our old fishless cycle/ammonia/from solutions calc). Will post
Well, I just ordered a gram scale so I can make some specific dKH solutions, and a second drop checker, so I will be awaiting your calculator to see if we can make this a useful tool.Yeah -- CAL AQUA LABS Double Drop Checker | Green Leaf Aquariums I have not ordered from these guys yet but am so impressed by their owner's openness and contributions to our hobby I am certain they're getting at least my next fert order.
Floated the idea above past a friend who likes it too, but (though have not looked seriously) I've not found what ranges or a formula to calculate what the low and upper thresholds for the color is. I'll build a little web calc for it where you can stick in a target CO2 and it will spit out how much baking soda (mg and tsp) to start the dilution with, derived from the current 4dKH for 30ppm CO2 colors we know of. With all the great calcs online today maybe it will still fill some niche. I need one that will do anything from mass percentage anyway (our old fishless cycle/ammonia/from solutions calc). Will post
Sweet. I will order a drop checker too: I am a little worried about the need for the pH reagent/Bromothymol blue but I figure worst case you can just dilute the stuff you got from Cal Aqua and Red Sea (say, adding 2dKH for a 6dKH solution, which would be green with 45ppm CO2).
I was mistaken about the Double Check drop checker by the way: in looking at pics its clear the reference solution never equalizes with aquarium water/gas. For this to work one needs two drop checkers, or perhaps just use the 6dKH solution if one wants to target more CO2. (I like high CO2 )
I;m just dropping in while waiting for a picture upload but will have the calc online soon after reading through existing drop checker posts. (This became popular after my first go round with the hobby and I currently know little to nothing about them.) <3
I was mistaken about the Double Check drop checker by the way: in looking at pics its clear the reference solution never equalizes with aquarium water/gas. For this to work one needs two drop checkers, or perhaps just use the 6dKH solution if one wants to target more CO2. (I like high CO2
)I;m just dropping in while waiting for a picture upload but will have the calc online soon after reading through existing drop checker posts. (This became popular after my first go round with the hobby and I currently know little to nothing about them.) <3
Yes I figured that out after reading the description. Too bad though because it looked nice. I found an ADA look alike on eBay for $8.50, free shipping.
Here you go: Calculators for planted nerds
Lots of folks have posted grams per tsp/TBL for NaHCO3/Baking Soda but I'll adjust the calc with a radio button or something after I buy some baking soda and do some weight trials this weekend. I'll probably throw in gallons for the mix container, too.
Would a mod or an admin mind breaking our fort and I's conversation about this idea into a new thread titled "Drop Checkers and target CO2" or something? <3
Lots of folks have posted grams per tsp/TBL for NaHCO3/Baking Soda but I'll adjust the calc with a radio button or something after I buy some baking soda and do some weight trials this weekend. I'll probably throw in gallons for the mix container, too.
Would a mod or an admin mind breaking our fort and I's conversation about this idea into a new thread titled "Drop Checkers and target CO2" or something? <3
Thanks, Purrbox!
Per request, the form now accepts one decimal for the mix container. (For example, ".5" or "0.5" L for 500mL.)
Also adjusted a couple things in the directions (pointing out to dilute, etc) just in case.
<3
Per request, the form now accepts one decimal for the mix container. (For example, ".5" or "0.5" L for 500mL.)
Also adjusted a couple things in the directions (pointing out to dilute, etc) just in case.
<3
Sweet!! Can't wait for my scale and my second drop checker to get here.
Looks like there is a problem though - something isn't calculating correctly. Tells me .08 grams of soda for a 2L bottle, and .03 grams of soda for a 6L mix...
Looks like there is a problem though - something isn't calculating correctly. Tells me .08 grams of soda for a 2L bottle, and .03 grams of soda for a 6L mix...
Thanks for messing with it, fort! Its just a rounding error but I'll bet it confuses other people, too -- I changed it back to 3 figures after the decimal for peace of mind and a better ballpark when weighing.
(For those considering this, a scale that can do tenth of a gram (100mg) increments is more than adequate for most any plant nerd's needs, with you rounding the difference, though some folks (ie Plantbrain, Edward, etc ) like more precise scales and measurement devices.)
(For those considering this, a scale that can do tenth of a gram (100mg) increments is more than adequate for most any plant nerd's needs, with you rounding the difference, though some folks (ie Plantbrain, Edward, etc
) like more precise scales and measurement devices.)My mistake, fort! Thank you for catching that! When doing the conversion for NaHCO3/Baking Soda from dKH I accidentally placed the dilution volume in the wrong spot... fixed.
* while at it also adjusted NaHCO3 equivalent of dKH/CaCO3 conversion to 8 sig figs while at it though still rounds to three decimal places when spitting out instructions.
Also gallon conversion for the mixing container.
Happy to post formulas or source code if anyone wants them, of course. I'll get back to work now...
* while at it also adjusted NaHCO3 equivalent of dKH/CaCO3 conversion to 8 sig figs while at it though still rounds to three decimal places when spitting out instructions.
Also gallon conversion for the mixing container.
Happy to post formulas or source code if anyone wants them, of course. I'll get back to work now...
elwaine
Aquarium Advice Activist
- Joined
- Nov 11, 2008
- Messages
- 174
Significant numbers and drop checkers
Gadzooks! It's the old significant numbers principle. I think that the accuracy inherent in colorimetric determination of dissolved CO2 isn't great enough to allow you to get the information you are seeking with your double bubble experiment. Drop checkers can only give you a range of values (see below).
I have very accurate scales and my reference solution is exactly 4 dKH. I added enough Bromothymol Blue to turn the reference solution a very bright rich green. I made up enough of that solution to fill a reference vial as well as filling my drop checker. But my eyes can only read the color of the fluid in the drop checker to an accuracy of + or - .2 pH, especially when trying to read the color of the liquid in my drop checker when it is in the aquarium (where it belongs)... even with the white center post in the Cal Aqua drop checker.
It is difficult to assess the "true" color of the fluid - either in the drop checker or in my standard reference vial - when attempting to read the color through the water column in my aquarium. When I remove the reference vial - or the drop checker - from the aquarium, the accuracy of color interpretation improves a little... but probably not to a significant extent
So if the actual KH of my aquarium water is 6, and my accuracy reading the color of the fluid is + or - .2 pH (based on color of the solution), the pH could be 7.0, 6.8, or 6.6... which corresponds to dissolved CO2 levels of 18 ppm, 29 ppm, and 45 ppm respectively.
Even if your eyes are better at differentiating colors than mine are, the color chart accompanying the various indicator dyes are only accurate to .2 pH. And that means that checking the level of dissolved CO2 via changing colors in a drop checker - even when the fluid within it is known to be a specific, accurately determined, dKH - can only tell you a range of values.
Most articles I've read about using drop checkers appreciate that problem (I think) because they simply state that if the color is green, the amount of dissolved CO2 is good; if it's yellow, there is too much CO2; and if it's blue, there is not enough CO2 dissolved in the water. So, with a dKH solution of 4, green represents about 30 ppm CO2 (actually more like 25 to 40 ppm CO2).
Am I making any sense here (or have I once again tipped the glass a wee bit too much this evening)? Anyway, that's why I bought the single bubble with the white center post, rather than the double bubble. And truth be told, while the white center post sounds like a good idea, I find that it does not help to improve my color estimates.
Gadzooks! It's the old significant numbers principle. I think that the accuracy inherent in colorimetric determination of dissolved CO2 isn't great enough to allow you to get the information you are seeking with your double bubble experiment. Drop checkers can only give you a range of values (see below).
I have very accurate scales and my reference solution is exactly 4 dKH. I added enough Bromothymol Blue to turn the reference solution a very bright rich green. I made up enough of that solution to fill a reference vial as well as filling my drop checker. But my eyes can only read the color of the fluid in the drop checker to an accuracy of + or - .2 pH, especially when trying to read the color of the liquid in my drop checker when it is in the aquarium (where it belongs)... even with the white center post in the Cal Aqua drop checker.
It is difficult to assess the "true" color of the fluid - either in the drop checker or in my standard reference vial - when attempting to read the color through the water column in my aquarium. When I remove the reference vial - or the drop checker - from the aquarium, the accuracy of color interpretation improves a little... but probably not to a significant extent
So if the actual KH of my aquarium water is 6, and my accuracy reading the color of the fluid is + or - .2 pH (based on color of the solution), the pH could be 7.0, 6.8, or 6.6... which corresponds to dissolved CO2 levels of 18 ppm, 29 ppm, and 45 ppm respectively.
Even if your eyes are better at differentiating colors than mine are, the color chart accompanying the various indicator dyes are only accurate to .2 pH. And that means that checking the level of dissolved CO2 via changing colors in a drop checker - even when the fluid within it is known to be a specific, accurately determined, dKH - can only tell you a range of values.
Most articles I've read about using drop checkers appreciate that problem (I think) because they simply state that if the color is green, the amount of dissolved CO2 is good; if it's yellow, there is too much CO2; and if it's blue, there is not enough CO2 dissolved in the water. So, with a dKH solution of 4, green represents about 30 ppm CO2 (actually more like 25 to 40 ppm CO2).
Am I making any sense here (or have I once again tipped the glass a wee bit too much this evening)? Anyway, that's why I bought the single bubble with the white center post, rather than the double bubble. And truth be told, while the white center post sounds like a good idea, I find that it does not help to improve my color estimates.
Larry,
Certainly using a drop checker will not give us an extremely accurate picture of our exact co2 concentration, but as u stated it does provide a range of estimation. By using 2 different reference kh solutions, it seems to me that we can narrow this range even more. While this certainly isn't going to be a perfect estimation, 2 checkers will narrow our measured range, and certainly be within a range acceptable for the information we are hoping to glean from a double drop check setup. Of course, I think you could make the arguement that it will not be all that much more valuable than just using a single checker with calibrated solution, but for a nerd like me, the more data available to me the better.
Certainly using a drop checker will not give us an extremely accurate picture of our exact co2 concentration, but as u stated it does provide a range of estimation. By using 2 different reference kh solutions, it seems to me that we can narrow this range even more. While this certainly isn't going to be a perfect estimation, 2 checkers will narrow our measured range, and certainly be within a range acceptable for the information we are hoping to glean from a double drop check setup. Of course, I think you could make the arguement that it will not be all that much more valuable than just using a single checker with calibrated solution, but for a nerd like me, the more data available to me the better.
elwaine
Aquarium Advice Activist
- Joined
- Nov 11, 2008
- Messages
- 174
Good point fort. Besides, that double drop checker looks cool Maybe I should have gotten one. Oh well...
Maybe I should have gotten one. Oh well...My bubble... you burst it Great post, elwaine. I think like not realizing this will be exactly like when I hated using test kits (though I do like the test tube playing pretend scientist part), I need to have the drop checkers in front of me to see if there's any ideas to bounce back. Without the drop checkers and any experience I can only bounce ideas off you guys as thought experiments, but I hope you'll entertain it:
It is also interesting that lots of folks make mention of adding enough CO2 until they see green, then adding a little more until they see yellow green. Your points about seeing shades of green hits hard for me: I am terrible with colors. Extra tough is its not as if I can adjust CO2 in very small increments with my particular needle valve, wait a few hours, look at the color again, then remember what the color was a few hours ago. But a difference in color (say, from whats totally green to whats a weird yellow green) still sounds easier to see... I wonder if we could adjust our CO2 targets for that.
Anyway, if we run with elwaine's +/-.2 pH, this becomes much hairier since, for example, +/- .2 pH is -10 / + 20 ppm CO2 with 4dKH, but is - 15 / +25 ppm CO2 at 6dKH.
(I could add that CO2 margin of error to the calculator based on +/- .2pH off of the resulting dKH of the solution. Sure the .2 pH is an estimate, but as fort said all we're really doing is trying to make a smaller ballpark... What do you guys think?)
To type this out for myself and anyone else who may be wondering if they want to drop the ~$25 (using fort's eBay suggestion for two drop checkers plus the baking soda) or a little more from GreenLeaf:
Let's say I have a drop checker with 3dKH (23ppm CO2 target) and its green. It says I have ~15-35ppm CO2.
I have a second drop checker with 6dKH (45ppm CO2 target) and it is green. It says I have ~30-70ppm CO2.
I use both. Now I know I have 30-35ppm CO2.
(With a 4dKH sample, using the .2pH/color margin of error ballpark, you have between 20 and 50ppm CO2.)
Also, to clarify, the "Double Check" drop checker from Cal Aqua won't work. Maybe someone else makes a design that will work as one unit (instead of two drop checkers, because, you know, thats only going to lead to having to make another tank for the extra drop checker later... ).
Great post, elwaine. I think like not realizing this will be exactly like when I hated using test kits (though I do like the test tube playing pretend scientist part), I need to have the drop checkers in front of me to see if there's any ideas to bounce back. Without the drop checkers and any experience I can only bounce ideas off you guys as thought experiments, but I hope you'll entertain it:It is also interesting that lots of folks make mention of adding enough CO2 until they see green, then adding a little more until they see yellow green. Your points about seeing shades of green hits hard for me: I am terrible with colors. Extra tough is its not as if I can adjust CO2 in very small increments with my particular needle valve, wait a few hours, look at the color again, then remember what the color was a few hours ago. But a difference in color (say, from whats totally green to whats a weird yellow green) still sounds easier to see... I wonder if we could adjust our CO2 targets for that.
Anyway, if we run with elwaine's +/-.2 pH, this becomes much hairier since, for example, +/- .2 pH is -10 / + 20 ppm CO2 with 4dKH, but is - 15 / +25 ppm CO2 at 6dKH.
(I could add that CO2 margin of error to the calculator based on +/- .2pH off of the resulting dKH of the solution. Sure the .2 pH is an estimate, but as fort said all we're really doing is trying to make a smaller ballpark... What do you guys think?)
To type this out for myself and anyone else who may be wondering if they want to drop the ~$25 (using fort's eBay suggestion for two drop checkers plus the baking soda) or a little more from GreenLeaf:
Let's say I have a drop checker with 3dKH (23ppm CO2 target) and its green. It says I have ~15-35ppm CO2.
I have a second drop checker with 6dKH (45ppm CO2 target) and it is green. It says I have ~30-70ppm CO2.
I use both. Now I know I have 30-35ppm CO2.
(With a 4dKH sample, using the .2pH/color margin of error ballpark, you have between 20 and 50ppm CO2.)
Also, to clarify, the "Double Check" drop checker from Cal Aqua won't work. Maybe someone else makes a design that will work as one unit (instead of two drop checkers, because, you know, thats only going to lead to having to make another tank for the extra drop checker later...
).
Last edited:
elwaine
Aquarium Advice Activist
- Joined
- Nov 11, 2008
- Messages
- 174
Borat's approach to Dump and Bump fertilization
Next question: Is there a difference in plant growth if one gauges the levels of CO2 as being between 25 - 45 ppm vs 30 - 35 ppm? Intuitively, one might think the answer would be "yes - greater precision over one of many variable factors determining plant growth would allow for better plant growth."
Me? I think that the answer would be, "Not so much." There are so many variables affecting plant growth that it would be a real challenge to prove, or disprove.
I don't mean to be a stickler here. Part of my career was spent evaluating experimental design before assessing validity of reported results. It just seems counter intuitive to use gross "Dump and Bump" fert schemes (aka, EI) - to avoid rate limiting values from developing - and then focus on tightening up CO2 dosing in order to achieve better plant growth. Anyone happy with EI should be happy with a single bubble drop checker with a 4 dKH solution and run their CO2 at a bubble count rate that turns the color in the bubble yellow green (not green). That way, CO2 would be closer to 45 ppm than 25 ppm and would not be rate limiting.
Yakshemash! I like the US and A.
Next question: Is there a difference in plant growth if one gauges the levels of CO2 as being between 25 - 45 ppm vs 30 - 35 ppm? Intuitively, one might think the answer would be "yes - greater precision over one of many variable factors determining plant growth would allow for better plant growth."
Me? I think that the answer would be, "Not so much." There are so many variables affecting plant growth that it would be a real challenge to prove, or disprove.
I don't mean to be a stickler here. Part of my career was spent evaluating experimental design before assessing validity of reported results. It just seems counter intuitive to use gross "Dump and Bump" fert schemes (aka, EI) - to avoid rate limiting values from developing - and then focus on tightening up CO2 dosing in order to achieve better plant growth. Anyone happy with EI should be happy with a single bubble drop checker with a 4 dKH solution and run their CO2 at a bubble count rate that turns the color in the bubble yellow green (not green). That way, CO2 would be closer to 45 ppm than 25 ppm and would not be rate limiting.
Yakshemash! I like the US and A.
Similar threads
