DIY Drop Checker For Under $1
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 > DIY


Reply
 
Thread Tools Display Modes
Old 07-22-2009, 04:46 AM   #1
tjbuege
Algae Grower
 
PTrader: (0/0%)
Join Date: Jun 2009
Location: Maplewood, Minnesota
Posts: 28
Default

DIY Drop Checker For Under $1


Having read numerous posts on this and other forums, I couldn't bring myself to spend upwards of $70 or more for a couple drop checkers for my tanks. So I decided to take a trip to my local surplus store, The Axe Man. I'm not sure if they are a nation-wide store, but there are a few around the Twin Cities here. They have just about anything you might need, at (usually) great prices. So, with some ideas in mind, I set out to see what I could find. And this is what I came up with:



The small glass bottle has a plastic cap with a hole in the center. Included was some sort of foam or plastic gasket/seal. The test tube is plastic (important as you will see).

What I did was to punch a hole in the gasket with a paper punch, just a tad bit smaller than the diameter of the test tube. Then I cut off the closed end of the test tube to allow air to flow through it. I suppose I could have used some plastic tubing from the local hardware store, but this was cheaper and available. Next, I push the test tube through the gasket, screw on the cover, grab a spare suction cup and attach with a rubber band, and viola! No waiting for glue to dry, and very easy to change the solution, since the cap is removable.

I tested filled with water for leaks, and found none. I am using DIY 4 KH solution (if anyone wants the details on how I made that, I can follow up with another post). Here is a picture of it in action:



It's a bit on the blue side in this shot, but I took this picture about 7 hours after the CO2 and lights went out.

My only concern with this setup is, it takes about 4 hours or more before I get a nice light green color. The indicator solution is VERY slow to change, but it does change. I suspect maybe my test tube doesn't have a large enough diameter to allow maximum air / gas exchange. I may play with this later on.

Anyhow, cost break down is this:

Glass bottle with cap = $0.35
Test tube = $0.15
Rubber band = free
Suction cup = free
Indicator solution = essentially free

Total cost = $0.50 and about 10 minutes of time.

Please comment. I'm open to suggestions for improvement.

Tim
tjbuege is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 07-22-2009, 05:08 AM   #2
deondrec
Algae Grower
 
PTrader: (3/100%)
Join Date: Sep 2008
Location: phoenix, arizona
Posts: 141
Default

great diy. I dont have a Axe Man store in arizona. You should make more and ship them. If the price was right i would buy at least 2.
deondrec is offline   Reply With Quote Quick reply to this message
Old 07-22-2009, 05:13 AM   #3
Darkblade48
Moderator
 
Darkblade48's Avatar
 
PTrader: (3/100%)
Join Date: Jan 2008
Location: Japan
Posts: 9,432
Default

Very similar to a build I made a few years back.
__________________
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 Quick reply to this message
Old 07-22-2009, 05:25 AM   #4
tjbuege
Algae Grower
 
PTrader: (0/0%)
Join Date: Jun 2009
Location: Maplewood, Minnesota
Posts: 28
Default

To deondrec: Thanks. I was considering making addition ones and placing several in my tanks, in various spots, to get an indication of CO2 concentrations and dispersion throughout the tank. With regards to building these for others, I wish I could say yes, but I'm not sure I have the time for that. Besides, I'm not convinced the design is optimal just yet. I bet you could find similar parts at any surplus or dollar store. Even if you had to drill your own hole in the cap and use silicon adhesive to fix a plastic tube in place, it would still be a simple project, and not cost much at all. Oh, and the nature of the Axe Man store is, their product can turn over quickly, depending on what it is. There's no guarantee the parts will be there for long. Some items will be here today, and gone tomorrow. Other items, like that Iron Lung (!) have been there for the 30+ years I've been visiting the store! (I guess there just isn't a demand for antiquated medical equipment...)

To Darkblade48: how did yours perform? I'm trying to figure out what I can change to make the solution react more quickly. I have about 7-8ml of indicator solution in these. I bet if I had less solution, and a smaller air pocket, and a larger area for gas exchange between tank water and air pocket, this might react faster. Your thoughts?

Tim
tjbuege is offline   Reply With Quote Quick reply to this message
Old 07-22-2009, 05:31 AM   #5
CAM6467
Planted Tank Enthusiast
 
CAM6467's Avatar
 
PTrader: (13/100%)
Join Date: Feb 2009
Location: Alvarado, Texas
Posts: 592
Default

I understand the process of creating KH standard, but what did you use for the PH/CO2 indicator solution (i.e. the portion of the mix that changes color)?
__________________
"Success is not the goal, it's merely a byproduct!"
- The Fraternity of Dirt #66 -
Just because it's dirt doesn't make it low-tech.
CAM6467 is offline   Reply With Quote Quick reply to this message
Old 07-22-2009, 05:40 AM   #6
tjbuege
Algae Grower
 
PTrader: (0/0%)
Join Date: Jun 2009
Location: Maplewood, Minnesota
Posts: 28
Default

I simply used my pH test solution from Aquarium Pharmaceuticals. Turns my 4KH solution to a very rich blue color, indicating a pH of about 7.2. For testing pH, the instructions say to put 3 drops in 5ml of tank water. Since I have closer to 8ml of 4KH water in the drop checker, I added about 6 drops to make the color saturated enough to read, but not too much to turn it murky. In one of my tanks, I've managed to get it to a light yellow-green. I'm still experimenting with optimum CO2 dispersion in my other tank. But in both tanks, my plants begin to pearl quite a bit, so I believe the drop checker is working, and that I am approaching 30ppm CO2. But is just takes to long to change colors. Much longer than the average 2 hours or so that most people say.
tjbuege is offline   Reply With Quote Quick reply to this message
Old 07-22-2009, 07:00 AM   #7
Darkblade48
Moderator
 
Darkblade48's Avatar
 
PTrader: (3/100%)
Join Date: Jan 2008
Location: Japan
Posts: 9,432
Default

Quote:
Originally Posted by tjbuege View Post
I'm trying to figure out what I can change to make the solution react more quickly. I have about 7-8ml of indicator solution in these. I bet if I had less solution, and a smaller air pocket, and a larger area for gas exchange between tank water and air pocket, this might react faster.
I think the most important thing is the surface area available between the liquid/air interface. If you were to use a larger test tube, for example, it would likely decrease the time it took for the colour to change.

Quote:
Originally Posted by CAM6467 View Post
I understand the process of creating KH standard, but what did you use for the PH/CO2 indicator solution (i.e. the portion of the mix that changes color)?
You can use any pH indicator that is based on bromothymol blue (or you can just use bromothymol blue itself).

Quote:
Originally Posted by tjbuege View Post
For testing pH, the instructions say to put 3 drops in 5ml of tank water. Since I have closer to 8ml of 4KH water in the drop checker, I added about 6 drops to make the color saturated enough to read, but not too much to turn it murky.
I usually put 6-7 drops into 5 mL of the 4 dkH reference solution. The addition of more drops of the bromothymol blue indicator has no effect on the time it takes for the drop checker to change colours. As long as the solution remains translucent and is not opaque, you are fine.
__________________
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 Quick reply to this message
Old 07-22-2009, 05:24 PM   #8
Hoppy
Planted Tank Guru
 
Hoppy's Avatar
 
PTrader: (75/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 18,987
Default

For the fastest reaction time you need the area of the tank water to the air surface to be as large as it can be, with the length of the air path to the indicator water to be as short as it can be, with the area of the indicator water to air surface being as large as it can be, with the volume of the indicator water to be as small as it can be. The limit on reducing the volume of the indicator water is the difficulty in seeing the color if it is too small. Someone with lots of spare time, a good understanding of the science involved with this, and computer skills, could probably write a program to optimize all of the dimensions. That isn't me, on several counts.
__________________
Hoppy
Hoppy is offline   Reply With Quote Quick reply to this message
Old 07-22-2009, 05:35 PM   #9
tjbuege
Algae Grower
 
PTrader: (0/0%)
Join Date: Jun 2009
Location: Maplewood, Minnesota
Posts: 28
Default

Thanks, Hoppy. This is along the lines of what I was thinking. So if I were to get a larger diameter test tube or other type of tube, to use as an air passage, it would have the additional side effect of reducing the space to be filled by indicator fluid, thus reducing the volume of indicator needed to be able to read it. And I can make the air tube shorter as well. I'll see what I can find at my local home improvement store.

Tim
tjbuege is offline   Reply With Quote Quick reply to this message
Old 07-25-2009, 01:06 AM   #10
4f1hmi
Planted Tank Obsessed
 
4f1hmi's Avatar
 
PTrader: (81/100%)
Join Date: Apr 2009
Location: south orange county
Posts: 382
Default

Would the KH solution from aquarium pharmaceuticals works as my indicator or I would have to add something else?
__________________
BO - EHEIM PIMP # 378-


Aim High
4f1hmi is offline   Reply With Quote Quick reply to this message
Old 07-25-2009, 02:20 AM   #11
Craigthor
Planted Tank Guru
 
Craigthor's Avatar
 
PTrader: (188/100%)
Join Date: Sep 2007
Location: Dubuque, IA
Posts: 9,628
Default

Quote:
Originally Posted by 4f1hmi View Post
Would the KH solution from aquarium pharmaceuticals works as my indicator or I would have to add something else?
Nope, you will either need to buy or make a 4 DkH solution. You cna purchase it from Orlando at GLA or make it youself there is a good how to here somewhere I'm sure.

Craig
__________________
Rebooting...

Quote:
Originally Posted by cdwill View Post
"C'mon, they're just plants, man, no big deal -- try some"
Craigthor is offline   Reply With Quote Quick reply to this message
Old 07-25-2009, 03:00 PM   #12
Darkblade48
Moderator
 
Darkblade48's Avatar
 
PTrader: (3/100%)
Join Date: Jan 2008
Location: Japan
Posts: 9,432
Default

Quote:
Originally Posted by 4f1hmi View Post
Would the KH solution from aquarium pharmaceuticals works as my indicator or I would have to add something else?
Quote:
Originally Posted by Craigthor View Post
Nope, you will either need to buy or make a 4 DkH solution. You cna purchase it from Orlando at GLA or make it youself there is a good how to here somewhere I'm sure.
I believe 4f1hmi was asking whether the kH test kit reagent can be used as the indicator in the drop checker.

In short, the answer is no, you want to use bromothymol blue as the indicator. This is in the API pH (normal range) test kit. Adding the pH indicator reagent to a 4 dkH reference solution will give you a drop checker that will turn green when CO2 levels reach 30 ppm.
__________________
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 Quick reply to this message
Old 08-06-2009, 02:00 AM   #13
4f1hmi
Planted Tank Obsessed
 
4f1hmi's Avatar
 
PTrader: (81/100%)
Join Date: Apr 2009
Location: south orange county
Posts: 382
Default

Quote:
Originally Posted by Darkblade48 View Post
I believe 4f1hmi was asking whether the kH test kit reagent can be used as the indicator in the drop checker.

In short, the answer is no, you want to use bromothymol blue as the indicator. This is in the API pH (normal range) test kit. Adding the pH indicator reagent to a 4 dkH reference solution will give you a drop checker that will turn green when CO2 levels reach 30 ppm.
Thanks you for the info. I actually made the drop checker from this tread but used a plastic air tubing instead of a test tube. My only problem is the solution which turns green when I tried to use the 4dkh from API. I will buy the solution then.
__________________
BO - EHEIM PIMP # 378-


Aim High
4f1hmi is offline   Reply With Quote Quick reply to this message
Old 08-06-2009, 02:09 AM   #14
kid creole
Wannabe Guru
 
PTrader: (2/100%)
Join Date: Dec 2008
Location: Raleigh, NC
Posts: 1,241
Default

To speed it up, use less water. The other pieces are going to be negligible, considering your geometry is defined already.
__________________
kid creole is offline   Reply With Quote Quick reply to this message
Old 08-06-2009, 04:43 PM   #15
Darkblade48
Moderator
 
Darkblade48's Avatar
 
PTrader: (3/100%)
Join Date: Jan 2008
Location: Japan
Posts: 9,432
Default

Quote:
Originally Posted by 4f1hmi View Post
My only problem is the solution which turns green when I tried to use the 4dkh from API. I will buy the solution then.
Not too sure what your problem is here; API doesn't make a 4 dkH solution.

Unless you meant to say that your reference solution immediately turns green when you add the API pH indicator (bromothymol blue) to it. If that is the case, either the test reagent is suspect, or the 4 dkH reference solution is not really 4 dkH.
__________________
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 Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may 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 12:40 PM.


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