OK I went and had a look. Rona has the dreaded black brush algae!!!! :evil:
Anyone managed to get rid of this without stripping the tank?
The following is an excerpt from www.thekrib.com in a disucssion on how BBA overtook one man's tank, after no problems for 3 years, and his attempts to get rid of it...
"It was an exasperating experience with many drastic measures taken (ie. UV water treatment for 3 weeks, Diatom filtering for days on end, assorted anti-algae treatments) lotsa advice was received but not much seemed to apply or work. From some of these rather radical tests did find out some interesting things about this BBA:
It has shown to survive a temperature range to 40 deg (F) to about 125 deg (F) as long as it has light.
Removal of light does not kill it it just suspends/retards its growth.
If a pile of it is removed it emits a real foul and pugnet smell immediately.
If you were to squish it between your fingers it seems to feel oily in texture.
Old Gravel with BBA on it that was used as a covering on several outdoor window box planters, retarded or limited the growth of the assorted outdoor pansys that were normally planted in them.
Old gravel that has wintered outdoors on the ground, put into a container with aquarium water and left in the sunshine, will exhibit new BBA growth within 4 - 6 weeks.
Tests at a LFS of every algaecide that they had, showed at best only a mild retarding of growth.
Water PH quality does not seem to affect its growth or propagation."
I found some sites said Siamese algae eaters would eat it and others said nothing would.
One man claimed to get rid of it using a syringe of hydrogen peroxide (although it also killed the plants).
Another site says use of CO2 gets rid of it.