DIY Drop Checker - Page 14 - DIY Aquarium Projects

hoppycalif · 12-12-2006, 09:48 AM

As best I can determine, bromothymol blue is the only pH indicator dye that gives yellow to blue readings, that is used in such test kits. There are a few others that give different colors, and for differenct pH ranges, but not for yellow to blue.

redstrat · 12-12-2006, 10:44 AM

Thats what I thought but figured I'd ask to be a little more confident with that assumption. Thanks

I just bought one of the Red Sea versions of the drop checker and I love it. I would almost consider a drop checker to be a must have item for anybody trying to get the most out of DIY Co2. I really like being able to adjust the "good" color to match the CO2 concentration I'm trying to achieve.

caymandiver75 · 12-13-2006, 05:32 AM

Quote:

Originally Posted by davis.1841

Thats what I thought but figured I'd ask to be a little more confident with that assumption. Thanks

I just bought one of the Red Sea versions of the drop checker and I love it. I would almost consider a drop checker to be a must have item for anybody trying to get the most out of DIY Co2. I really like being able to adjust the "good" color to match the CO2 concentration I'm trying to achieve.

Cool. I also have that Red Sea version drop checker and last night got some distilled water and baking soda and got the kh to 4. Place the drop checker back in the aquarium and within 2 hrs it went from Blue to Very very light green almost yellow.

jolywoo · 12-13-2006, 09:44 AM

I use the redsea version too with distilled water set to kh of 5. Looks like you have a good co2 in your water, even all the bba on your driftwood is gone.

caymandiver75 · 12-13-2006, 09:51 AM

Quote:

Originally Posted by jolywoo

I use the redsea version too with distilled water set to kh of 5. Looks like you have a good co2 in your water, even all the bba on your driftwood is gone.

Hehe yeah the BBA is gone because I took about an hour to scrape off all the algae, trim the plants that had it, etc. What a pain in the butt! Now that my water conditions are checked and I reduced my lighting I'm hoping the stuff never grows back. What little is left i'm praying my 6 Oto's will take care of.

Naja002 · 12-13-2006, 10:05 AM

Quote:

Originally Posted by hoppycalif

For those who don't read many other aquatic plant forums, Tom Barr did some experimenting with this device and came up with the idea that you could get rid of the air gap entirely, and speed up the response rate considerably, just by using a gas permeable membrane to hold the reference KH solution. Then, if that membrane is in the form of a stocking over the business end of a pH probe, you have a CO2 probe - with fast reaction and great accuracy. He has done a prototype, of sorts, and it works. And, he is working towards getting this available for all of us.

I would imagine, for testing purposes, that the "Breather Bags" that people use to ship fish in would work for a membrane--The Bag--let's C02 Out--Oxygen In. Reversed (into/toward the Drop checker): its should let the C02 In. But will it let it back Out to maintain equilibrium? Hmmmmmmmm.....

Needing one clarification: Drop Checker fluid--set to Kh 5 will read the same C02 ppm as what is in the Tank? Meaning regardless of tank Kh (2, 6, 8, 12 whatever) the ppm of C02 in the tank will match the Kh4 Soultion? I can almost grasp that, but it just doesn't seem right.......

I looked at the "Table" posted:

Table Link

And I'm just missing something. I'll re-read that a couple dozen more times and see if I can get it to "Click"........

Thanx!

redstrat · 12-13-2006, 10:21 AM

how the Distilled water with an adjusted KH works is this,
in the drop checker the solution will match the dissolved CO2 of the aquarium regardless of KH in either solution. Knowing this, we add an indicator such as Bromethyl blue(not sure about the spelling) that will show certain colors at a known PH. Using this we can adjust the PH of the indicator solution in the drop checker to change the color to green at the desired concentration of CO2 by manipulating the KH. for example a KH of 4 in the distilled water bromethyl blue solution will be green when the CO2 is at 30ppm, regardless the water chemestry in the aquarium. the whole point of this is to narrow the margin of error in our CO2 measurements.

Correct me if I'm wrong but by adjusting the KH in the solution what CO2 concentration will show green in the following using bromethyl blue indicator and distilled water and the KH adjusted using Baking Soda:
KH3 Green = 20ppm CO2?
KH4 Green = 30ppm CO2
KH5 Green = 40ppm CO2?

These are all +/- 5ppm, correct?

I'm not sure about exact numbers here but i know qualitativly this should be correct I hope it helps clear some things up.

caymandiver75 · 12-13-2006, 10:46 AM

Yeah according to Hoppy on the 1st page.

"Here are the color charts for the three commonly used pH test kit reagents. For the top one, it is yellow at pH of 6.0, blue at 7.2, and green (the middle) at 6.6."

You can verify this by plugging in the KH and respectable PH into the following calculator to verify your results. CLICK HERE

Naja002 · 12-13-2006, 10:46 AM

Ok, Thanx. I understand what You are saying and I actually was typing out a response when I think it clicked. So, let me see if I have this right:

X-amount of C02 will create X-ppm regardless of Kh.

The Higher the Kh--the more C02 it will take to create X-amount of change in pH.

BUT, since we are not concerned with the pH in the Tank--it becomes irrelevent. The focus is on the pH change in the Drop-Checker because 30ppm is 30ppm--regardless of Kh, Correct?

If we matched the Kh to that of the Tank--then we would just be chasing the "Color Scale" and making it more difficult, Correct?

I think I've got it--just need confirmation.....

caymandiver75 · 12-13-2006, 10:58 AM

Quote:

Originally Posted by Naja002

Ok, Thanx. I understand what You are saying and I actually was typing out a response when I think it clicked. So, let me see if I have this right:

X-amount of C02 will create X-ppm regardless of Kh.

The Higher the Kh--the more C02 it will take to create X-amount of change in pH.

BUT, since we are not concerned with the pH in the Tank--it becomes irrelevent. The focus is on the pH change in the Drop-Checker because 30ppm is 30ppm--regardless of Kh, Correct?

If we matched the Kh to that of the Tank--then we would just be chasing the "Color Scale" and making it more difficult, Correct?

I think I've got it--just need confirmation.....

I'm in the same boat. I'm sure someone will come here and give us confirmation. Taking a look at this chart that is from the same page as the CO2 calculator link in my previous post it does appear that the higher the Kh--the more C02 it will take to create X-amount of change in pH.