[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Aquatic Plants Digest V4 #191

Michael Rubin wrote:

> At night when the lights are off the
> plants aren't drawing carbon from the CO2 so your pH returns from 7.0 to
> 6.6.  Adding an airstone at night will drive the CO2 off and your pH will
> rise, perhaps dangerously fast.

I'd just like to report that my own use of an airstone at
night has been very successful, and doesn't seem to bother
the fish.  I do have a pH rise, but I'm not convinced that fish
are affected by pH to any appreciable degree.

I have a 70-gallon ex-high tank (36" x 14" x 30") that has a
relatively small surface area for it's volume.  My fish load is
also quite high.  And my Fluval cannister provides good
circulation but without much surface disruption at all.  If I
let the surface plants overgrow a bit and further decrease
the circulation at the surface, the fish will show distress at
night.  I've even managed to kill a few SAEs this way.  So
when I decided to get my CO2 going for real, I added an
airstone that is on when the lights are off.

My water now stays saturated with oxygen around the
clock, as evidenced by the java ferns starting to bubble
within 30 minutes of the light coming on in the morning.
My CO2 level and hence the pH do swing around a bit,
but it really doesn't seem to be a problem.  I have been 
watching the fish, looking for any signs of stress, but 
I haven't seen any.  Happy plants and happy fish.

David Ozenne
Fremont, CA