CO2 and calcium question - The Planted Tank Forum
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 03-15-2007, 02:03 PM Thread Starter
Planted Tank Obsessed
fredyk's Avatar
PTrader: (21/100%)
Join Date: Jan 2004
Location: Arlington, VA
Posts: 314
Question CO2 and calcium question

There is one area about which I am uncertain, pertaining to CO2 and calcium.

Salwater aquarists use CO2 for calcium reactors. So one would think that CO2 is having an effect on calcium in our freshwater planted tanks, dissolving the calcium.

How does this affect the water hardness, and how would it affect snails and shrimp?
For example, I do weekly water changes and use CO2, but the nerites snails shells have large fissures in the shell, and so have been moved to another tank without CO2.
Does one need to add calcium, oyster-coral shells, or do water changes to compensate for dissolved calcium? I'm just curious about the relationship about CO2 and calcium disolving.


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.

Last edited by fredyk; 03-15-2007 at 10:24 PM.
fredyk is offline  
Sponsored Links
post #2 of 3 (permalink) Old 03-16-2007, 12:33 AM
Planted Tank Enthusiast
KevinC's Avatar
PTrader: (6/100%)
Join Date: May 2004
Location: Oshkosh, WI
Posts: 738
In short, yes, CO2 will accelerate the dissolving of calcium salts (like limestone and snail shells).

Longer: other than the snail shells, you don't need or want anything else in the tank that is made of calcium salts. As it dissolves it will raise the GH (and KH if limestone). This is somewhat uncontrolled - and makes it more difficult to control your CO2 level using a pH controller. If you have a level of 3 or more dGH, your snails will survive and you probably have enough Ca for the plants - though your Mg might be a little low if you are only at 3dGH.



72g bowfront planted, CO2, 4x - T5HO, Eheim 2213 and 2217, 2 angels, pristella tetras, blue tetras, betta, albino bristlenose pleco, albino cories. Sword, vals, hygros, ludwigias, java moss and fern, anubias

2g Mac-quarium. Clown gravel, fluorescent plastic plants, and 2 guppies.
KevinC is offline  
post #3 of 3 (permalink) Old 03-16-2007, 01:23 AM
Planted Tank Guru
Rex Grigg's Avatar
PTrader: (65/100%)
Join Date: Dec 2002
Location: Portland Orygun
Posts: 9,600
Reef tanks need a continual supply of calcium because that's what reefs are made of. If you let the calcium supply in a reef tank drop too low many bad things happen, like expensive livestock dying.

That's just not the case in a FW planted aquarium. In fact most people can supply plenty of calcium in a FW planted aquarium by just doing a water change.
Rex Grigg is offline  


Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


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