drop checker - instantly green
Planted Tank Forums
Your Tanks Image Hosting *Tank Tracker * Plant Profiles Fish Profiles Planted Tank Guide Photo Gallery Articles

Go Back   The Planted Tank Forum > Specific Aspects of a Planted Tank > Equipment


Reply
 
Thread Tools Display Modes
Old 04-05-2013, 03:47 PM   #1
WheeledGoat
Planted Tank Obsessed
 
WheeledGoat's Avatar
 
PTrader: (1/100%)
Join Date: Mar 2013
Location: Chicago
Posts: 324
Default

drop checker - instantly green


I got
this drop checker this drop checker
, and like the design a lot (it's a lot smaller than you'd guess from the pictures.

I ignored the included directions to use tank water and mixed up my own 4kh solution (distilled water & fresh baking soda), verified per my kh test kit to be between 4-5 (barely perceptible change on 4th drop, fast and strong change on 5th - perfect! damn I'm good. lol jk, I just followed directions).

I filled the drop checker with my 4kh solution, and added 5 drops of the "co2 test solution" included with the drop checker. I was surprised to see that it was yellow; I was expecting it to be blue (I read somewhere that it is bromthymol blue for the pH test). It looked more like the color of my high pH test solution...

After adding the 5 drops, the solution turned green. At first I was like YAY! but then I was like... wait. It's supposed to be green when there's ~30ppm co2 in the water. Should it be blue right now?

I used distilled water off the grocery store shelf - it was not uncapped long before I had my final solution in the drop checker.

Any theories? co2 in the distilled water? don't use the included reagent, instead try the pH test solution out of my kit?
WheeledGoat is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 04-05-2013, 03:52 PM   #2
TexasCichlid
Surrounded by Blyxa
 
TexasCichlid's Avatar
 
PTrader: (27/100%)
Join Date: Jul 2011
Location: Texas
Posts: 1,504
Default

Try the pH solution from your kit.
TexasCichlid is offline   Reply With Quote
Old 04-05-2013, 06:03 PM   #3
Darkblade48
Moderator
 
Darkblade48's Avatar
 
PTrader: (3/100%)
Join Date: Jan 2008
Location: Toronto
Posts: 9,100
Default

Quote:
Originally Posted by TexasCichlid View Post
Try the pH solution from your kit.
+1. If you are using a normal range pH test kit made by API, then it is without a doubt, bromothymol blue.

Other brands most likely use the same reagent, but I have not investigated them, so do not know for certain.

If the API pH test kit also turns green, then you have probably made the reference solution incorrectly.
__________________
Anthony

A Primer to Pressurized CO2 and A Primer to Planted Tanks
Eheim Pimp #362 - Eheim 2213 x2, Eheim 2028, Eheim 2217, Eheim surface skimmer and Eheim autofeeder.
Victor Pimp #33 - HPT272-125-350-4M
Darkblade48 is offline   Reply With Quote
Old 04-05-2013, 06:14 PM   #4
thinBear
Planted Member
 
thinBear's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2011
Location: Bay Area, CA
Posts: 237
Default

I had very similar situation as well. I tried both the reagent came with the DC from Taiwan as well as the API pH test kit, same green color;
You may test the pH of your distilled water, usually distilled water tends to absorb CO2 and turns acidic (mine was down to 6.2)
After several hours, my DC turns blue (CO2 off of coz) and MAY works normal now.

I think inside a closed container(distilled water bottle and the 4dkH container) , CO2 have no chance to escape thus it gives green color.
thinBear is offline   Reply With Quote
Old 04-05-2013, 06:24 PM   #5
WheeledGoat
Planted Tank Obsessed
 
WheeledGoat's Avatar
 
PTrader: (1/100%)
Join Date: Mar 2013
Location: Chicago
Posts: 324
Default

Quote:
Originally Posted by Darkblade48 View Post
If the API pH test kit also turns green, then you have probably made the reference solution incorrectly.
definitely appreciate the input and your expertise! Where could I have gone wrong with the reference solution? I used distilled water, sodium bicarbonate as fresh as I can get it, and the kh tests out pretty much right on the mark. what would I fix?
WheeledGoat is offline   Reply With Quote
Old 04-05-2013, 06:32 PM   #6
gSTiTcH
Planted Tank Enthusiast
 
gSTiTcH's Avatar
 
PTrader: (5/100%)
Join Date: Feb 2013
Location: Jacksonville, Florida
Posts: 838
Default

In my tiny drop checker, I only use 2 drops of reagent. Maybe 5 is far too much for that container?
gSTiTcH is offline   Reply With Quote
Old 04-05-2013, 06:36 PM   #7
WheeledGoat
Planted Tank Obsessed
 
WheeledGoat's Avatar
 
PTrader: (1/100%)
Join Date: Mar 2013
Location: Chicago
Posts: 324
Default

A customer review under that product on amazon says that his was green initially, too. hmm! Sure would make sense if the distilled water's pH was off, being sealed up and all.

That still doesn't address the fact that the test solution that came with the DC is yellow/orange, and not blue...

If the DC isn't blue when I get home (co2 isn't turned on yet in the tank - the assembled setup is in place under the aquarium and taunting me to just plug in the solenoid) I'll reset it with my kit's pH test solution and see what that looks like. I'll also test the pH of my 4dkh solution as well as the distilled water.

Quote:
Originally Posted by gSTiTcH View Post
In my tiny drop checker, I only use 2 drops of reagent. Maybe 5 is far too much for that container?
I donno! the instructions said to use 5 drops, but then again, the instructions also said to use tank water.. LOL

Last edited by Darkblade48; 04-05-2013 at 09:10 PM.. Reason: Please use the edit function for back to back posts.
WheeledGoat is offline   Reply With Quote
Old 04-05-2013, 09:16 PM   #8
Darkblade48
Moderator
 
Darkblade48's Avatar
 
PTrader: (3/100%)
Join Date: Jan 2008
Location: Toronto
Posts: 9,100
Default

Quote:
Originally Posted by WheeledGoat View Post
definitely appreciate the input and your expertise! Where could I have gone wrong with the reference solution? I used distilled water, sodium bicarbonate as fresh as I can get it, and the kh tests out pretty much right on the mark. what would I fix?
I don't know what instructions you followed to make the 4 dkH reference solution, so cannot comment on this.

Quote:
Originally Posted by gSTiTcH View Post
In my tiny drop checker, I only use 2 drops of reagent. Maybe 5 is far too much for that container?
No; normally, the number of drops will not be relevant. Adding 2 drops versus 5 drops will not change anything (other than making the colour darker). Of course, if half your solution is bromothymol blue, then it becomes a different story.

Quote:
Originally Posted by WheeledGoat View Post
That still doesn't address the fact that the test solution that came with the DC is yellow/orange, and not blue...
When I prepare my bromothymol blue, it only appears dark blue/black when I have a significant volume. When dropping it from a Pasteur pipette, it appears yellow/brown to me.
__________________
Anthony

A Primer to Pressurized CO2 and A Primer to Planted Tanks
Eheim Pimp #362 - Eheim 2213 x2, Eheim 2028, Eheim 2217, Eheim surface skimmer and Eheim autofeeder.
Victor Pimp #33 - HPT272-125-350-4M
Darkblade48 is offline   Reply With Quote
Old 04-06-2013, 02:51 PM   #9
WheeledGoat
Planted Tank Obsessed
 
WheeledGoat's Avatar
 
PTrader: (1/100%)
Join Date: Mar 2013
Location: Chicago
Posts: 324
Default

I got home last night and the drop checker was blue. nice. flipped on the co2 solenoid!

Bingo - I tested the distilled water: pH = 6 (or less - it's yellow and that's the lower limit for my kit)
interestingly, my sealed up 4kh soln comes in at pH = 7.4 - 7.6 as of this morning. I suppose it had time to degas. (It should have for as much as I stirred and mixed - but if it degassed when I was mixing, that doesn't help explain the insta-green reading. And, obviously, the added NaHCO3 would have a buffering effect.... blah. whatever.)


Quote:
Originally Posted by Darkblade48 View Post
I don't know what instructions you followed to make the 4 dkH reference solution, so cannot comment on this.
I weighed 12g NaHCO3, mixed into 1L for a 400dKH soln, and diluted from there for 4dHK.

I just tested 10ml and it turned for a moment on the 8th drop when I mixed, but turned back quickly. The 9th drop brought the change, so I'm happily between 4 - 4.5 dHK.
WheeledGoat is offline   Reply With Quote
Old 04-06-2013, 04:07 PM   #10
thinBear
Planted Member
 
thinBear's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2011
Location: Bay Area, CA
Posts: 237
Default

Quote:
Originally Posted by WheeledGoat View Post
I got home last night and the drop checker was blue. nice. flipped on the co2 solenoid!

Bingo - I tested the distilled water: pH = 6 (or less - it's yellow and that's the lower limit for my kit)
interestingly, my sealed up 4kh soln comes in at pH = 7.4 - 7.6 as of this morning. I suppose it had time to degas. (It should have for as much as I stirred and mixed - but if it degassed when I was mixing, that doesn't help explain the insta-green reading. And, obviously, the added NaHCO3 would have a buffering effect.... blah. whatever.)




I weighed 12g NaHCO3, mixed into 1L for a 400dKH soln, and diluted from there for 4dHK.

I just tested 10ml and it turned for a moment on the 8th drop when I mixed, but turned back quickly. The 9th drop brought the change, so I'm happily between 4 - 4.5 dHK.
Good to hear that, gives me extra little confidence coz I was wondering the reason my DC turns blue was due to:
  • evaporation of solution inside DC > condensed the baking soda > higher kH and alkalinity > turns reagent blue (My DC was setup inside a DSM now), or
  • trapped CO2 escaped as mentioned earlier
Quote:
Where could I have gone wrong with the reference solution? I used distilled water, sodium bicarbonate as fresh as I can get it, and the kh tests out pretty much right on the mark. what would I fix?
When we have limited access to lab grade equipments, there will be a lot can go wrong, for example:
  • contaminated containers (the cups, funnels, bottles, media you put on the weight for holding chemicals...etc), error can be reduced by rising with distilled water several times and air dry them
  • un-calibrated measuring tools including kitchen measuring cup, digital scale, kH and pH test kit
  • contaminated materials: like u said, baking soda will absorb moisture and turns into another chemical, distilled water could be not so pure if something goes wrong when manufactured or during packing
keep in mind DC only give a rough estimation at specific spot with some time delay. So we may not need to aim for so much accuracy.

Last edited by thinBear; 04-06-2013 at 11:41 PM.. Reason: typo
thinBear is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 01:51 PM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright Planted Tank LLC 2012