Re: [RML] plant bubbles

Michael Eckardt (mike at
Wed, 7 Mar 2001 10:38:55 -0500

The water in the mains is under pressure (65psi or so)and has dissolved
atmospheric gases in it. Like a soda drink when you open the bottle, the gas
will escape from the aquarium water after a waterchange.
The plants, producing O2 by way of photosynthesis, are pumping the O2 into
this water that is supersaturated with O2 (and other gases) and the bubbles
simply escape. The bubble from the plants are O2.

Having said this, this happens only immediately after the waterchange. If
the bubbling continues for days after the waterchange, then your fertilizer
regime is missing an ingredient which is supplied by the waterchange.

Michael Eckardt

----- Original Message -----
From: "Tyrone Genade" <Tgenade at>
To: <rainbowfish at>
Sent: March 7, 2001 6:14 AM
Subject: Re: [RML] plant bubbles

On 6 Mar 2001, at 23:20, Ed wrote:

> ~~~
> Why do plant make bubbles after a water change
> and what gas is in them

depends, do you have hard or alkaline water? if so the plants can
be metabolizing the bicarbonate to make CO2 which they then use
to make sugar and O2.

It is hard to say without knowing what the water is like. Most plants
suffer from a CO2 shortage in fishtanks and will 'fix' CO2 at night
using it in the day. This applies to most plants except surface or
floating plants. With a suply of HCO3- the plants will rapidly use it
if there is strong light to make their food and waster: O2 which
normally constitiute the bubbles seen on plants.
Also, with the water change alot more gasses would of disolved
into the water with the added aggitation.

Just a few thoughts. I doubt it is anything harmful if the plants are
still fine.


Tyrone Genade
tyronegenade at

P450 Lab, Biochemistry Department
University of Stellenbosch, 7602, South Africa
Ph: +27-021-808-5876, fax: +27-021-808-5863

"Those who trust in the Lord for help will find their
strength renewed."
Isaiah 40:31