How much does CO2 affect PH - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old 05-09-2011, 08:58 AM Thread Starter
Planted Tank Guru
 
waterfaller1's Avatar
 
PTrader: (70/100%)
Join Date: Jul 2006
Location: Florida
Posts: 5,310
Send a message via AIM to waterfaller1
How much does CO2 affect PH

As the title states, is there a way to calculate, or a rule of thumb?
waterfaller1 is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old 05-09-2011, 12:07 PM
Algae Grower
 
Duckweed hunter's Avatar
 
PTrader: (1/100%)
Join Date: Feb 2011
Location: CT
Posts: 100
The more co2 the bigger the drop...I go by my drop checker and a Ph controller

Sent from my PC36100 using Tapatalk
Duckweed hunter is offline  
post #3 of 13 (permalink) Old 05-09-2011, 02:29 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Mar 2010
Location: Toronto, Canada
Posts: 44
Does kh effect the ph drop and reading?
penpal is offline  
 
post #4 of 13 (permalink) Old 05-09-2011, 02:57 PM
Planted Tank Guru
 
PTrader: (84/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 21,012
If there is nothing in the water affecting the pH, except for carbonates and CO2, the equation that describes the effect of CO2 on the pH is:
ppm of CO2 equals KH of the water times 3 times ten raised to the power of 7 minus the pH. But, aquarium or tap water contains other things affecting the pH, such as tannins, phosphates, and various chemicals added to the water by the water department to keep the pH high. Another way to look at that relationship is to notice that it means that if you increase the dissolved CO2 by a factor of 10, the pH will drop by 1.0.

Hoppy
Hoppy is offline  
post #5 of 13 (permalink) Old 05-09-2011, 03:19 PM
Planted Tank Enthusiast
 
Vancat2's Avatar
 
PTrader: (3/100%)
Join Date: Jun 2010
Location: Vernon, CT
Posts: 612
Vancat2 is offline  
post #6 of 13 (permalink) Old 05-09-2011, 06:17 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Feb 2011
Location: Hillsboro, Oregon
Posts: 149
Thumbs up

...this is golden!

Quote:
Originally Posted by Hoppy View Post
... the equation that describes the effect of CO2 on the pH is:
ppm of CO2 equals KH of the water times 3 times ten raised to the power of 7 minus the pH.

...it's about the fish.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Stevenicoloconnor is offline  
post #7 of 13 (permalink) Old 05-10-2011, 12:55 AM
Planted Tank Guru
 
plantbrain's Avatar
 
PTrader: (267/100%)
Join Date: Dec 2003
Location: The swamp
Posts: 13,609
Quote:
Originally Posted by waterfaller1 View Post
As the title states, is there a way to calculate, or a rule of thumb?
Relative drops can work okay I think.
Even with tannins and what not in the water..........but it is relative.

So eyeballing and slow small progressive adjustments are wise.

Adjust, observe and measure for 3-4 days, adjust a tiny bit and so on.......
I use the needle valve and the rate of CO2 addition, not the pH however. (Ask yourself why I do this.)




Regards,
Tom Barr
plantbrain is offline  
post #8 of 13 (permalink) Old 05-10-2011, 01:46 AM Thread Starter
Planted Tank Guru
 
waterfaller1's Avatar
 
PTrader: (70/100%)
Join Date: Jul 2006
Location: Florida
Posts: 5,310
Send a message via AIM to waterfaller1
Quote:
Originally Posted by plantbrain View Post
(Ask yourself why I do this.)
Because you are Tom Barr...
waterfaller1 is offline  
post #9 of 13 (permalink) Old 05-10-2011, 03:36 AM
Wannabe Guru
 
btimmer92's Avatar
 
PTrader: (67/99%)
Join Date: Mar 2011
Location: Dayton, Ohio
Posts: 1,227
So, Tom, you just make small changes to the bubble count, observe , and repeat?

-Bill



btimmer92 is offline  
post #10 of 13 (permalink) Old 05-10-2011, 05:04 AM
Planted Tank Guru
 
plantbrain's Avatar
 
PTrader: (267/100%)
Join Date: Dec 2003
Location: The swamp
Posts: 13,609
Quote:
Originally Posted by btimmer92 View Post
So, Tom, you just make small changes to the bubble count, observe , and repeat?
No, the bubble count is rather imprecise.

A nice vernier handle(these can be DIY with a little paint and add a fat knob etc or buy one etc........) is a better tool for this ona good quality needle valve.
The only other way I know is a mass flow controller, these run about 1200$, but are extremely accurate(should be for the cost).

The rate of CO2 is independent of effects on pH/KH in the tank itself, if you use pH.........this can and does move around, as can KH.

However, the absolute addition of CO2 or the ppm is relatively stable with the valve method. Only degas rates(so keep the tank topped off good) that might change, circulation(you do not want clogged filters etc) or increase/decrease in plant biomass and uptake become the main players(keep tank pruned consistently).

So basic maintenance is more an issue using this method as with any, but not much else once set.




Regards,
Tom Barr
plantbrain is offline  
post #11 of 13 (permalink) Old 05-10-2011, 09:08 AM Thread Starter
Planted Tank Guru
 
waterfaller1's Avatar
 
PTrader: (70/100%)
Join Date: Jul 2006
Location: Florida
Posts: 5,310
Send a message via AIM to waterfaller1
This tank is not a conventional set up.. ie: filter ..etc. I am not sure how effective CO2 might even be. It is a 90 gallon reef ready tank converted to fresh. So, built in overflow, leads to sump, through filter sock, past UV, over media bags w/ Eheim media, over baffle, return by external pump.
waterfaller1 is offline  
post #12 of 13 (permalink) Old 05-10-2011, 04:07 PM
Planted Tank Guru
 
PTrader: (84/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 21,012
You can modify the reef tank so it will work ok with CO2. Tom can explain that part. And, the reason Tom can adjust CO2 the way he does is that he has loads of experience judging how the plants look, about how much CO2 will be needed, and how to be observant with a planted tank. Those of us who haven't achieved that experience yet, can use a drop checker as a crutch to help us get close to having a good level of CO2, instead of fumbling around at low CO2 levels thinking we might be killing our fish. For some people they say courage comes in a bottle, but for planted tank keepers, it can come in the form of a drop checker.

Hoppy
Hoppy is offline  
post #13 of 13 (permalink) Old 05-10-2011, 07:35 PM Thread Starter
Planted Tank Guru
 
waterfaller1's Avatar
 
PTrader: (70/100%)
Join Date: Jul 2006
Location: Florida
Posts: 5,310
Send a message via AIM to waterfaller1
Great analogy. I bow to all of the great green mean machines at TPT!
waterfaller1 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



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