newbie, CO2, observations, and algae - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 08-31-2005, 01:02 AM Thread Starter
Guest
 
PTrader: (0/0%)
Join Date: Mar 2004
Posts: 228
newbie, CO2, observations, and algae

At the risk of .....mis-using this forum, I want to share with you an observation.

As a newbie to aquariums, and as someone discovering the mysteries of setting one up in somewhat of a vacuum, I discovered

1.5 bubbles/sec of CO2 with a kh of 4 gives me a ph of about 6.6 and CO2 of about 30ppm

and

3 bubbles/sec of CO2 with a kh of 4 gives me a ph of about 6.4 and CO2 of about 48 ppm

It's easy to see where a newbie might not want to DOUBLE the injected bubble/sec rate for fear of sending CO2 through the roof. Of course this is exactly what may be needed to reduce algae.

It is almost impossible to get the subtle nuance from reading these forums that really can only come with experience.
mikey is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 08-31-2005, 02:19 AM
Doesn't like Kool-Aid
 
Momotaro's Avatar
 
PTrader: (52/100%)
Join Date: Feb 2003
Location: Hawthorne, New Jersey
Posts: 10,125
Great observation, Mikey!

That is the main reason you can't trust a bubble count to give you an accurate CO2 level. You need to use the pH/KH relationship.

Sometimes it doesn't take much to crash a pH!

Mike

[SIGPIC][/SIGPIC]
Momotaro is offline  
post #3 of 9 (permalink) Old 08-31-2005, 04:23 AM
Planted Tank Guru
 
plantbrain's Avatar
 
PTrader: (267/100%)
Join Date: Dec 2003
Location: The swamp
Posts: 13,609
pH/CO2/KH tabkleas are good for an estimate, but they can be promblematic as well, then the experience part comes into play as well as knowing precisely what poor CO2 appears like with many plant species.........

CO2 complacency gets everyone at some point.


Regards,
Tom Barr



plantbrain is offline  
 
post #4 of 9 (permalink) Old 09-01-2005, 07:07 PM Thread Starter
Guest
 
PTrader: (0/0%)
Join Date: Mar 2004
Posts: 228
Hey Mike,

you're right about that -

What I meant was - I do calculate the CO2 each time with pH and KH ....
it's just that by doubling the bubble/sec rate from 15bps to 30bps my KH remained the same, and my pH only dropped by .2 (from 6.6 to 6.4).

It was surprising that doubling the CO2 bps rate, the pH barely changed!!
mikey is offline  
post #5 of 9 (permalink) Old 09-01-2005, 07:16 PM
Wannabe Guru
 
shalu's Avatar
 
PTrader: (1/100%)
Join Date: Jan 2003
Location: San Jose, CA
Posts: 1,675
You also need to consider the fact that the higher the CO2 level in water, the faster CO2 leakes back into air. So it gets harder to increase CO2 levels further. This is particularly true when you have some surface agitation. That little agitation will leak more CO2 when CO2 level is high.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Flourite, wet/dry, AHSupply 302w PC, PinPoint controller

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
15w T6+15w T8

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
40w T6 ODNO4x, no CO2. Discus grow out.
10gallon Tonina tank, 2x15w T6 ODNO 4x
---------------------
I will do aquascapes after I collect all the plant species and grow them to perfection.
shalu is offline  
post #6 of 9 (permalink) Old 09-01-2005, 08:09 PM
Are these real?
 
Wasserpest's Avatar
 
PTrader: (194/100%)
Join Date: Jun 2003
Location: Monterey, CA
Posts: 15,634
And, pH is measured using a logarithmic scale, so each step means a 10-fold change in H+ ions.

So, pH 6 has 10 times the concentration of H+ ions (acidity) as pH 7.

If you expected the pH to drop from 6.6 to 3.3... well you shouldn't have.


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.

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.
Wasserpest is offline  
post #7 of 9 (permalink) Old 09-01-2005, 08:17 PM
Wannabe Guru
 
shalu's Avatar
 
PTrader: (1/100%)
Join Date: Jan 2003
Location: San Jose, CA
Posts: 1,675
but the CO2/ph/kh relationship already takes that into account.... CO2 in ppm is directly proportional to the volume(bubbles) of CO2 dissolved in water. So what Mikey was expecting is not unreasonable. In his first post, he expected another 30ppm CO2, but only 18ppm according to the chart. I don't think he was looking for a linear ph/CO2 relationship.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Flourite, wet/dry, AHSupply 302w PC, PinPoint controller

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
15w T6+15w T8

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
40w T6 ODNO4x, no CO2. Discus grow out.
10gallon Tonina tank, 2x15w T6 ODNO 4x
---------------------
I will do aquascapes after I collect all the plant species and grow them to perfection.
shalu is offline  
post #8 of 9 (permalink) Old 09-01-2005, 09:02 PM
Are these real?
 
Wasserpest's Avatar
 
PTrader: (194/100%)
Join Date: Jun 2003
Location: Monterey, CA
Posts: 15,634
Quote:
Originally Posted by mikey
it's just that by doubling the bubble/sec rate from 15bps to 30bps my KH remained the same, and my pH only dropped by .2 (from 6.6 to 6.4).

It was surprising that doubling the CO2 bps rate, the pH barely changed!!
Quote:
Originally Posted by shalu
I don't think he was looking for a linear ph/CO2 relationship.
I must have misread his post then... Just treat my response as another unnecessary piece of information


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.

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.
Wasserpest is offline  
post #9 of 9 (permalink) Old 09-01-2005, 09:15 PM
Wannabe Guru
 
shalu's Avatar
 
PTrader: (1/100%)
Join Date: Jan 2003
Location: San Jose, CA
Posts: 1,675
ok, he did sound like it in the second post, LOL. Anyway, the non-linear relationship does make accurate gauging of CO2 difficult at high concentration: small error in ph results in large error in CO2 estimate.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Flourite, wet/dry, AHSupply 302w PC, PinPoint controller

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
15w T6+15w T8

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
40w T6 ODNO4x, no CO2. Discus grow out.
10gallon Tonina tank, 2x15w T6 ODNO 4x
---------------------
I will do aquascapes after I collect all the plant species and grow them to perfection.
shalu 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