Most accurate CO2 test? - The Planted Tank Forum
 50Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 45 (permalink) Old 10-20-2018, 05:12 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Aug 2011
Location: Germantown, TN
Posts: 125
Most accurate CO2 test?

Trying to determine how much CO2 I can add. I’d rather not just push it till the fish react adversely. Don’t think simply watching how much the pH drops is a good way - but will certainly set a floor limit on my controller. Any suggestions?

240 gallon Neptune Apex controlling 2 FX6's, 4 Kessil 360X Tuna Sun's, 2 EcoTech PM40's, GLA SS-Pro, DOS, BRS dosing pump and 2 Finnex 800w heaters
jnboone is offline  
Sponsored Links
Advertisement
 
post #2 of 45 (permalink) Old 10-20-2018, 05:16 PM
Planted Tank Enthusiast
 
MCFC's Avatar
 
PTrader: (0/0%)
Join Date: Feb 2017
Location: BC, Canada
Posts: 794
Quote:
Originally Posted by jnboone View Post
Donít think simply watching how much the pH drops is a good way
Why not?
Maryland Guppy likes this.

Blue Moon Rising!!!

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



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(Retired)
MCFC is offline  
post #3 of 45 (permalink) Old 10-20-2018, 05:18 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Aug 2011
Location: Germantown, TN
Posts: 125
Because I donít think you can you use that to determine how many ppm CO2 that you have


Sent from my iPhone using Tapatalk
Edward likes this.

240 gallon Neptune Apex controlling 2 FX6's, 4 Kessil 360X Tuna Sun's, 2 EcoTech PM40's, GLA SS-Pro, DOS, BRS dosing pump and 2 Finnex 800w heaters
jnboone is offline  
 
post #4 of 45 (permalink) Old 10-20-2018, 05:19 PM
Planted Tank Guru
 
Maryland Guppy's Avatar
 
PTrader: (15/100%)
Join Date: Dec 2014
Location: Arnold
Posts: 3,690
Minimum 1.0 drop in pH
MCFC likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Growing is not that difficult.
Maryland Guppy is offline  
post #5 of 45 (permalink) Old 10-20-2018, 05:24 PM
Planted Tank Enthusiast
 
MCFC's Avatar
 
PTrader: (0/0%)
Join Date: Feb 2017
Location: BC, Canada
Posts: 794
Quote:
Originally Posted by jnboone View Post
Because I donít think you can you use that to determine how many ppm CO2 that you have

What reasoning has brought you to that conclusion?

The pH drop seems to be used by the people who grow the best plants/have the nicest tanks...


Sent from my iPhone using Tapatalk

Blue Moon Rising!!!

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



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(Retired)
MCFC is offline  
post #6 of 45 (permalink) Old 10-20-2018, 05:28 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Aug 2011
Location: Germantown, TN
Posts: 125
Iím not saying pH drop isnít good. I bought a controller to manage that. Iím simply saying I donít know how to use pH drop to accurately determine ppm CO2


Sent from my iPhone using Tapatalk
Edward likes this.

240 gallon Neptune Apex controlling 2 FX6's, 4 Kessil 360X Tuna Sun's, 2 EcoTech PM40's, GLA SS-Pro, DOS, BRS dosing pump and 2 Finnex 800w heaters
jnboone is offline  
post #7 of 45 (permalink) Old 10-20-2018, 05:33 PM
Planted Tank Guru
 
Maryland Guppy's Avatar
 
PTrader: (15/100%)
Join Date: Dec 2014
Location: Arnold
Posts: 3,690
It's not just from the people that grow the plants.

The manufacturers of high end submersible monitoring equipment also use pH to derive a signal.

Here is an excerpt from such.

"A diaphragm-type glass electrode based on the electrochemical principle is employed for this CO2 gas sensor. According to this principle, when CO2 gas passes through the diaphragm and dissolves in the inner solution, the pH of the solution changes. Because the change of the pH is proportional to the CO2 concentration, the degree of change is measured to determine the CO2 concentration. The following figure indicates the relationship, which exhibits good linearity characteristics, between the CO2 concentration and the electric potential of the glass electrode."


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Growing is not that difficult.
Maryland Guppy is offline  
post #8 of 45 (permalink) Old 10-20-2018, 05:45 PM
Planted Tank Enthusiast
 
aubie98's Avatar
 
PTrader: (1/100%)
Join Date: Apr 2017
Location: Nashville, TN
Posts: 712
I get the sense that there are 2 main camps re: co2 monitoring:

1. use a drop checker and try to manage a good lime green color
2. measure ph and shoot for a go for a 1 ph drop

The problem with #1 is that co2 (carbonic acid in the aquarium) isn't the only thing affecting ph in the tank, so the co2/kh/ph relationship that the drop checker is based on is inherently inaccurate. What degree of inaccuracy actually exists is dependent on the individual tank, so could be right on the nose and some could be wildly off target.

Using a ph monitor/controller/meter is a better option b/c with it you've eliminated the kh aspect of the relationship (I think). Because you are accurately measuring only one thing now (ph), you can target a specific co2 level independent of any knowledge of the kh in the tank. if you aim for a 1 ph drop you'll be roughly in the neighborhood of 30 ppm co2. At least that's my understanding of the issue, more knowledgeable people can chime in and correct me if I'm off-target.
akd200 likes this.

There was only one catch and that was Catch-22.

Last edited by aubie98; 10-20-2018 at 05:47 PM. Reason: premature posting
aubie98 is offline  
post #9 of 45 (permalink) Old 10-20-2018, 05:46 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Sep 2018
Posts: 8
Quote:
Originally Posted by Maryland Guppy View Post
It's not just from the people that grow the plants.

"A diaphragm-type glass electrode based on the electrochemical principle is employed for this CO2 gas sensor. According to this principle, when CO2 gas passes through the diaphragm and dissolves in the inner solution, the pH of the solution changes. Because the change of the pH is proportional to the CO2 concentration, the degree of change is measured to determine the CO2 concentration. The following figure indicates the relationship, which exhibits good linearity characteristics, between the CO2 concentration and the electric potential of the glass electrode."
OOOHHHHH SNAPSSS!!!! dropping knowledge

the drop checker is a proven method and
The PPM of CO2 will change constantly because the plants will take in different levels as they grow or propagate.
mstrgemz is offline  
post #10 of 45 (permalink) Old 10-20-2018, 05:47 PM
Planted Tank Guru
 
Greggz's Avatar
 
PTrader: (2/100%)
Join Date: May 2008
Location: Novi, MI
Posts: 5,036
Quote:
Originally Posted by jnboone View Post
Iím not saying pH drop isnít good. I bought a controller to manage that. Iím simply saying I donít know how to use pH drop to accurately determine ppm CO2
Well here's the thing, you will never know your CO2 ppm. Too many variables that could affect pH to get anything close to an absolute value.

However, for our purposes, it doesn't matter much. Like many things in this hobby, we are interested in relative value. And to determine relative value, pH drop is the best tool we have.

Take my tank. My KH is 3, and I drop my pH from 7.2 to 5.85. It doesn't even show up on the charts. With a calculator, it comes out at 127 ppm CO2. Now does that mean my CO2 ppm is actually 127ppm?

I doubt it....but it doesn't really matter. That's the level where my fish are still active and the plants are at their best. Which is good enough for me.
Edward, Immortal1, ChrisX and 3 others like this.


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

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
---
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
---
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Greggz is online now  
post #11 of 45 (permalink) Old 10-20-2018, 05:49 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Sep 2018
Posts: 8
U want to cut your CO2 via a ph controller if it drops by 1 ??

Bump: U want to cut your CO2 via a ph controller if it drops by 1 ??
mstrgemz is offline  
post #12 of 45 (permalink) Old 10-20-2018, 05:55 PM
Planted Tank Guru
 
Maryland Guppy's Avatar
 
PTrader: (15/100%)
Join Date: Dec 2014
Location: Arnold
Posts: 3,690
KH will never drop out of the equation.
Carbonate and bicarbonate will determine the buffering capability of the water.

Drop checkers react slow.

Targeting a 1.0 pH drop is just a starting pont.

Dissolved O2 and dissolved CO2 can both be maintained in the water column simultaneously.
Greggz, MCFC and ChrisX like this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Growing is not that difficult.
Maryland Guppy is offline  
post #13 of 45 (permalink) Old 10-20-2018, 06:01 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Aug 2011
Location: Germantown, TN
Posts: 125
I just set up a 240 I bought used and had to reseal. Also just started using CO2. I justified buying a Neptune Apex (which I have immediately fallen completely in love with!!!) because I could apply the funds I would have used to purchase a CO2 controller towards the Apex EL. I'm using pH drop to control my CO2. The bubble counter on my regulator is a little bit useless because the tank is so big (only able to tell that I'm adding more or less - and have ordered a flow meter thanks to this forum!). I obviously want to put as much CO2 into the tank as I can (without stressing the fish).

Other than seeing the fish seeking the surface, is there a maximum amount of pH drop that is a safe measurement? I'm guessing different species of fish have different tolerances for pH drop. I currently have only harlequin rasbora's, Congo's, roselike sharks, a red-tailed black shark, and a bristlenose pleco.

240 gallon Neptune Apex controlling 2 FX6's, 4 Kessil 360X Tuna Sun's, 2 EcoTech PM40's, GLA SS-Pro, DOS, BRS dosing pump and 2 Finnex 800w heaters
jnboone is offline  
post #14 of 45 (permalink) Old 10-20-2018, 06:03 PM
Planted Tank Enthusiast
 
MCFC's Avatar
 
PTrader: (0/0%)
Join Date: Feb 2017
Location: BC, Canada
Posts: 794
Drop and watch. Go low and slow.


Sent from my iPhone using Tapatalk
Greggz likes this.

Blue Moon Rising!!!

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



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(Retired)
MCFC is offline  
post #15 of 45 (permalink) Old 10-20-2018, 06:18 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Aug 2011
Location: Germantown, TN
Posts: 125
Thankfully the Apex will tell me if it shuts off the CO2 because the pH dropped to the limit I set (I really love the thing! Itís just amazing how many different ways you can use it! One little example is that I can look at my phone and see what the temp and pH is at that moment). The pH never dropped more than 1.1 yesterday, and the fish showed no signs of stress, so Iím going to increase the CO2 and set my limit to a 1.3 drop today while Iím home and can observe during the whole dosing period.


Sent from my iPhone using Tapatalk
Greggz and aubie98 like this.

240 gallon Neptune Apex controlling 2 FX6's, 4 Kessil 360X Tuna Sun's, 2 EcoTech PM40's, GLA SS-Pro, DOS, BRS dosing pump and 2 Finnex 800w heaters
jnboone is offline  
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



Similar Threads
Thread Thread Starter Forum Replies Last Post
CO2, pH and kH question, help needed :) brightstar123 Fertilizers and Water Parameters 29 01-08-2017 09:47 PM
Flaws in Kh chart regarding CO2 content Hardstuff General Planted Tank Discussion 29 09-20-2014 07:08 PM
Finally! Take 3 (pg15 or 16)! skabooya Low Tech Forum 272 11-28-2009 10:42 PM
Newbie's First Planted Tank Plan. Suggestions? Tips? Help? Diogenes General Planted Tank Discussion 4 11-24-2009 01:34 AM
CO2 revelations plantbrain General Planted Tank Discussion 174 04-02-2006 03:30 AM

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