Re: Blue-green algae and Hornwort

Paul Krombholz writes....

>Ceratophyllum does seem to make bluegreen algae (cyanobacteria) go away,
>and, in my experience, so does Hydrilla. The cyanobacteria doesn't seem to
>be killed, rather, it seems to stop growing and slowly diminish to nothing
>over a month or two.   Unfortunately, neither Ceratophyllum nor Hydrilla
>has any effect on green water algae.
>Diana Walstad has a good literature review of allopathy in aquatic plants
>and algae, starting in Vol. 8, number 4 of The Aquatic Gardener.

For what it is worth -which isn't much, B-G algae grows best for me in
a tank exclusively populated by hornwort. An identical sister tank,
hooked up to the same water system/lighting etc. and planted with
rosette plants of various ˇorts, has red but no B-G algae. The ONLY
difference is the water circulation/agitation. The one with the cyano-
bacteria is still; the fifteen gallon without it has an AquaClear Mini
providing surface movement. I do not believe that blue-green algae does
well in oxygenated water. On the other hand, I can't explain why it
often thrives attached to the outflow ledges of many AquaClears.

Dave Whittaker                       ac554 at FreeNet_Carleton.CA
Gloucester, Ontario                  dwhitt at magmacom_com