Question about CO2 drop checker - The Planted Tank Forum
 3Likes
  • 2 Post By OVT
  • 2 Post By Hoppy
  • 2 Post By OVT
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 08-19-2016, 02:24 PM Thread Starter
Planted Member
 
JuanSan's Avatar
 
PTrader: (2/100%)
Join Date: May 2014
Location: Albuquerque, New Mexico
Posts: 188
Question about CO2 drop checker

I recently added shrimp to my aquarium and thus lowered my carbon dioxide levels, and as a result started getting green spot algae. My question about drop checkers pertains to the the accuracy of the CO2 concentration when the kh levels vary between the internal drop checker environment and the external aquarium environment? We use a 4 dkh standard in the checker, however, my tank is around 9 dkh. Will the color indication of the drop checker be relevant to the actual concentration of the tank water?

The reason I ask is that I am getting a solid lime green-yellow hue to the checker and yet there is almost no pearling from the plants so its hard to tell whether I am supplying my plants enough co2.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JuanSan is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 08-19-2016, 03:14 PM
Planted Tank Guru
 
roadmaster's Avatar
 
PTrader: (1/100%)
Join Date: Nov 2009
Location: Missouri united states
Posts: 5,576
Drop checker water is isolated from tank water, and only reacts to direct contact from CO2 to my knowledge/understanding.
roadmaster is offline  
post #3 of 14 (permalink) Old 08-19-2016, 03:23 PM
Algae Grower
 
Calestus's Avatar
 
PTrader: (2/100%)
Join Date: Oct 2015
Location: Utah
Posts: 135
Check this out.
https://www.plantedtank.net/forums/26...er-works~.html

There is no contact between tank water and drop checker solution. So to answer your question, no, it doesn't matter what your tank water is at.

Pearling plants isn't really a good indicator of enough CO2.

If your drop checker turns a nice green color after a couple hours there's almost certainly enough enough CO2 in the water for the plants to do their thing. Remember, drop checkers tell you what your CO2 levels were at ~two hours ago.

Unless you are striving for every millimeter of growth a day that you possibly can, I wouldn't worry about it.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Calestus is offline  
 
post #4 of 14 (permalink) Old 08-19-2016, 03:24 PM Thread Starter
Planted Member
 
JuanSan's Avatar
 
PTrader: (2/100%)
Join Date: May 2014
Location: Albuquerque, New Mexico
Posts: 188
Quote:
Originally Posted by Calestus View Post
Check this out.
https://www.plantedtank.net/forums/26...er-works~.html

There is no contact between tank water and drop checker solution. So to answer your question, no, it doesn't matter what your tank water is at.

Pearling plants isn't really a good indicator of enough CO2.

If your drop checker turns a nice green color after a couple hours there's almost certainly enough enough CO2 in the water for the plants to do their thing. Remember, drop checkers tell you what your CO2 levels were at ~two hours ago.

Unless you are striving for every millimeter of growth a day that you possibly can, I wouldn't worry about it.
Quote:
Originally Posted by roadmaster View Post
Drop checker water is isolated from tank water, and only reacts to direct contact from CO2 to my knowledge/understanding.
Thanks for taking the time to respond. I don't know why I am having difficulty wrapping my head around this concept. So just to clarify, If my drop checker is a nice lime green regardless of the kh of the tank water, I do in fact have around 30 ppm of co2 circulating in the tank?

If I was getting slight amounts of BBA and GSA, knowing that I reduced my CO2 levels and them not being present before, would I look to other things causing my issue like excess nitrates?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by JuanSan; 08-19-2016 at 03:28 PM. Reason: Organization
JuanSan is offline  
post #5 of 14 (permalink) Old 08-19-2016, 03:49 PM
Algae Grower
 
Calestus's Avatar
 
PTrader: (2/100%)
Join Date: Oct 2015
Location: Utah
Posts: 135
"Added shrimp" The shrimp could have introduced your new algae friends and they are just capitalizing on their new home. Might go away once it burns through the available resources.

There's a thought that fluctuating CO2/PH triggers algae too.

Edit : You could build one of these.
http://www.santa-monica.cc/DROP2-dro...-day_p_47.html


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Calestus is offline  
post #6 of 14 (permalink) Old 08-19-2016, 03:53 PM Thread Starter
Planted Member
 
JuanSan's Avatar
 
PTrader: (2/100%)
Join Date: May 2014
Location: Albuquerque, New Mexico
Posts: 188
Quote:
Originally Posted by Calestus View Post
"Added shrimp" The shrimp could have introduced your new algae friends and they are just capitalizing on their new home. Might go away once it burns through the available resources.

There's a thought that fluctuating CO2/PH triggers algae too.
This is a really good point that I did not consider. There were some snail hitchhikers but I did not consider algae tagging along with them as well.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by JuanSan; 08-19-2016 at 03:54 PM. Reason: Condensed
JuanSan is offline  
post #7 of 14 (permalink) Old 08-19-2016, 07:30 PM
Planted Tank Guru
 
PTrader: (84/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 21,012
Reducing the amount of CO2 in the water by a large amount will almost always trigger a BBA outbreak. If you need to have about 30 ppm of CO2, you probably have high light and plants that require CO2 to grow well. That suggests that reducing the light intensity and growing less demanding plants could solve your problems.

Hoppy
Hoppy is offline  
post #8 of 14 (permalink) Old 08-19-2016, 07:52 PM Thread Starter
Planted Member
 
JuanSan's Avatar
 
PTrader: (2/100%)
Join Date: May 2014
Location: Albuquerque, New Mexico
Posts: 188
Quote:
Originally Posted by Hoppy View Post
Reducing the amount of CO2 in the water by a large amount will almost always trigger a BBA outbreak. If you need to have about 30 ppm of CO2, you probably have high light and plants that require CO2 to grow well. That suggests that reducing the light intensity and growing less demanding plants could solve your problems.
Thanks for taking the time to respond. This is a fair point. Most og my plants are medium light requiring at the moment including ammania sp. bonsai, ar 'mini', monte carlo and pogostegmon helferi. I have kept low light plants in the past and this is my first venture into high tech aquariums so I am still learning the finite balance between ferts, light, and co2.

About a month ago, I inadvertantly gassed my entie tank of shrimp when I had the co2 to high, so trying to learn from my mistakes, I went the other way and now had it bubbling to low.

I believe that another issue that I have been running into is excess nitrates so it was almost inevitable that I would have another small outbreak. I am addressing this with water changes and dripping the water back in to not have the shrimp go into TDS shock (another lesson that I learned the hard way).


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JuanSan is offline  
post #9 of 14 (permalink) Old 08-20-2016, 04:37 AM
Planted Tank Guru
 
PTrader: (84/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 21,012
Excess nitrates or phosphates have not been shown to cause algae outbreaks in planted tanks. Shortages of either can lead to some types of algae.

Hoppy
Hoppy is offline  
post #10 of 14 (permalink) Old 08-20-2016, 07:26 AM
OVT
Carpe Diem
 
OVT's Avatar
 
PTrader: (144/100%)
Join Date: Nov 2011
Location: NorCal
Posts: 7,474
Drop checker is a nifty invention and I take my hat off to thinking people who put 2 and 2 together and come up with inventions like that.

Drop checkers are visual aids at a very reasonable price and they provide an approximation of co2 concentration. To measure the co2 concentration in water more accurately currently requires more technology with a ~$2,000 price tag to start. Understanding how drop checkers work and their limitations helps us to set our expectations on what we actually get for $25 and how to use them to our best advantage.

The basics are rather simple (and beatiful): you have a liquid with known properties (aka reference solution which is usually RO water with 4 dKh). The reference solution is then mixed with several drops of pH reagent. The chemistry tells us that by adding co2 to that solution will drop the pH (CO2+H20 -> H2CO3). The drop in pH will change the color of the solution in a known fashion (blue to green to yellow) due to the reagent. Because we are dealing with known quantaties, the conversion of color to co2 concentration is calculatible (and rather linear).

The mixture goes into a small chamber with a very narrow neck (to prevent tank water from getting in). When we put a drop checker in a tank, we create an almost closed system:

Reference solution in a glass / plastic (i.e. non-porous) chamber -> atmospheric air acting as a water barrier -> tank water.

Taking a step back, we examine our system to think about what we got:

- the solution is "isolated" and (theoretically) the tank water does not get mixed in
- for anything to get to the solution has no place to come from but from the tank water
- for anything to get to the solution it has to be in gaseous form to get through the air barrier

Therefore, the basic idea here is that co2 (gas) escapes from the tank water into the drp checker. The color of the drop checker will change based on how much co2 makes it to the solution. Brilliant, imho.

And that's the theory, as I understand it. All nice and well.

Now, to all the thinking people out there, why this nifty, scientifically backed-up tool:
- would "lie"?
- what are the limitations?
- why is it analogous to a, say, a chain saw?

In conjuction with before mentioned post https://www.plantedtank.net/forums/26...er-works~.html, I hope my monolog will provide more food for thought.

PS: to add more wood to the fire, concentrations of co2 at that "magic" 30 ppm and above are possible. But I content that the probability for most of us actually getting to that 30 is rather slim, regardless of what your drop checker tells you.
natemcnutty and natemcnutty like this.

Courtesy * Integrity * Perseverance * Indominable Spirit * and Self Control
Tenets of TKD

Last edited by OVT; 08-20-2016 at 07:36 AM. Reason: sp
OVT is online now  
post #11 of 14 (permalink) Old 08-20-2016, 01:58 PM Thread Starter
Planted Member
 
JuanSan's Avatar
 
PTrader: (2/100%)
Join Date: May 2014
Location: Albuquerque, New Mexico
Posts: 188
Quote:
Originally Posted by Hoppy View Post
Excess nitrates or phosphates have not been shown to cause algae outbreaks in planted tanks. Shortages of either can lead to some types of algae.
I get the sense that you have mentioned this to newcomers a time or two. Do you have any papers that i can read on the matter to better educate myself?

Quote:
Originally Posted by OVT View Post
Drop checker is a nifty invention and I take my hat off to thinking people who put 2 and 2 together and come up with inventions like that.

Drop checkers are visual aids at a very reasonable price and they provide an approximation of co2 concentration. To measure the co2 concentration in water more accurately currently requires more technology with a ~$2,000 price tag to start. Understanding how drop checkers work and their limitations helps us to set our expectations on what we actually get for $25 and how to use them to our best advantage.

The basics are rather simple (and beatiful): you have a liquid with known properties (aka reference solution which is usually RO water with 4 dKh). The reference solution is then mixed with several drops of pH reagent. The chemistry tells us that by adding co2 to that solution will drop the pH (CO2+H20 -> H2CO3). The drop in pH will change the color of the solution in a known fashion (blue to green to yellow) due to the reagent. Because we are dealing with known quantaties, the conversion of color to co2 concentration is calculatible (and rather linear).

The mixture goes into a small chamber with a very narrow neck (to prevent tank water from getting in). When we put a drop checker in a tank, we create an almost closed system:

Reference solution in a glass / plastic (i.e. non-porous) chamber -> atmospheric air acting as a water barrier -> tank water.

Taking a step back, we examine our system to think about what we got:

- the solution is "isolated" and (theoretically) the tank water does not get mixed in
- for anything to get to the solution has no place to come from but from the tank water
- for anything to get to the solution it has to be in gaseous form to get through the air barrier

Therefore, the basic idea here is that co2 (gas) escapes from the tank water into the drp checker. The color of the drop checker will change based on how much co2 makes it to the solution. Brilliant, imho.

And that's the theory, as I understand it. All nice and well.

Now, to all the thinking people out there, why this nifty, scientifically backed-up tool:
- would "lie"?
- what are the limitations?
- why is it analogous to a, say, a chain saw?

In conjuction with before mentioned post https://www.plantedtank.net/forums/26...er-works~.html, I hope my monolog will provide more food for thought.

PS: to add more wood to the fire, concentrations of co2 at that "magic" 30 ppm and above are possible. But I content that the probability for most of us actually getting to that 30 is rather slim, regardless of what your drop checker tells you.
You are a beautiful individual for this write up. I actually had a dream about this last night coming to a similar conclusion in my train of thoughts. but you string it together so eloquently. I think my major break through came when i started thinking about it as an isolated system with only gas being able to react with the solution in the drop checker. Once again thank you for your write up. This should be a sticky note for for future writeups on dropcheckers.

Last edited by Darkblade48; 08-21-2016 at 08:20 AM. Reason: Please use the edit function for back to back posts to keep threads cleaner
JuanSan is offline  
post #12 of 14 (permalink) Old 08-20-2016, 04:05 PM
Planted Tank Guru
 
PTrader: (84/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 21,012
Quote:
Originally Posted by JuanSan View Post
I get the sense that you have mentioned this to newcomers a time or two. Do you have any papers that i can read on the matter to better educate myself?
No, I don't. Scientific papers are almost always aimed at natural bodies of water, where fertilizer run-off raises the nitrate and phosphate concentrations. For those situations excessive nitrate or phosphate do cause algae blooms. I'm not at all sure why aquariums don't behave the same way. However, a great many planted tank hobbyists have used the EI dosing method which often leads to higher than desired concentrations of nutrients, and they don't get algae if they have a good level of CO2 in the water for every photoperiod. I don't doubt that there are some situations in aquariums where you might have algae problems that go away if you reduce the levels of nutrients in the water, but that is certainly not the usual result. You can do a lot of reading here: Estimative Index - Aquarium Plants - Barr Report and learn more about this. Dr. Tom Barr is very well regarded, world-wide, for his approach to planted tanks, and he is also a scientist.
JuanSan and JuanSan like this.

Hoppy
Hoppy is offline  
post #13 of 14 (permalink) Old 08-23-2016, 03:04 AM Thread Starter
Planted Member
 
JuanSan's Avatar
 
PTrader: (2/100%)
Join Date: May 2014
Location: Albuquerque, New Mexico
Posts: 188
Quote:
Originally Posted by Hoppy View Post
No, I don't. Scientific papers are almost always aimed at natural bodies of water, where fertilizer run-off raises the nitrate and phosphate concentrations. For those situations excessive nitrate or phosphate do cause algae blooms. I'm not at all sure why aquariums don't behave the same way. However, a great many planted tank hobbyists have used the EI dosing method which often leads to higher than desired concentrations of nutrients, and they don't get algae if they have a good level of CO2 in the water for every photoperiod. I don't doubt that there are some situations in aquariums where you might have algae problems that go away if you reduce the levels of nutrients in the water, but that is certainly not the usual result. You can do a lot of reading here: Estimative Index - Aquarium Plants - Barr Report and learn more about this. Dr. Tom Barr is very well regarded, world-wide, for his approach to planted tanks, and he is also a scientist.
This is not the first time that someone has recommended EI dosing for my tank. I have been dosing via the PPS-PRO method to limit nutrients added to the tank, however, this method is becoming increasingly more appealing as daily dosing can become somewhat arduous or I flat out forget. I really should inform myself with teh Barr report more, everyone highly recommends it.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by JuanSan; 08-23-2016 at 03:04 AM. Reason: concision
JuanSan is offline  
post #14 of 14 (permalink) Old 08-23-2016, 06:40 AM
OVT
Carpe Diem
 
OVT's Avatar
 
PTrader: (144/100%)
Join Date: Nov 2011
Location: NorCal
Posts: 7,474
With high light / injected co2 you pretty much have to dose daily.

With plants, there are 2 driving factors: light and nutrients (macros, micros and co2). Mr Barr contents that driving up light and most nutrients is relatively easy except co2. The idea behind EI, which Mr Barr populirized, is to safely drive the nutrients up so that we can concentrate on the hard part - co2.

The primary premise behind EI is that excess nutrients do not cause algae blooms but lack of one or more nutrients do.

As to the OP, I was hoping to get other people's oppinions why drop checkers are more "dangerous" then usefull and the reasons behind that statement.
Hoppy and Hoppy like this.
OVT is online now  
Reply

Tags
None

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:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome