Directional Change of CO2 mist = Rotting Java Fern


Prolific Poster
Dec 27, 2006
Hello All...

So, I changed the direction of my CO2 misting in the middle of last week. I moved the spray of the CO2 to point more in the direction of a specific Java Fern I have in my tank (not to hit the fern more, just to spray more in that general direction of the tank). After a few days that specific java fern started to turn black. As of today the entire fern had turned black and was rotting away, so I trimmed all the leaves. The rhizome is still in-tact so I expect it will grow some new leaves soon.

My question... is this expected? Did the change of the CO2 misting direction cause the fern to rot? Is it the change in the available levels of CO2 that caused it to die back? None of the other plants showed any signs of illness/rotting/dying. I am thinking this is an issue of consistency. That is the only change I have made in the last 2-3 months.

Some other info if necessary
- 29 gallon tank doing EI
- 65 Watts of PC lighting raised above the tank.
- Drop checker is light green with compressed CO2.



Prolific Poster
Apr 5, 2006
I have experienced my ferns turning black in several occations, when i moved them from a low light, low CO2 tank - to a higher lighted, high CO2 tank.
I dont know whether its the adjustment to better/differnt conditions, that makes the fern to "shut down" the old leafes (these start to form new rhizomes, as a propagation method), but soon new and fresher leafes starts to form form the old rhizome.

I just trim the big, old black leafes away, and soon you have e nice fresh plant...

Old plant

Same plant a few weeks after, and after i trimmed the old leafes away:


Tom Barr

Staff member
Jan 23, 2005
Ditto what AP said. give them some time to acclimate.

Tom Barr