Well back in the Uk again at last !.
Thanks for the link "adeyc".
I read most of the articles on this stuff and its exactly what happens in my tank.
You hoover up all the thick green carpet of gunge only to find it comes back faster and stronger. Interesting to find out that its bacteria and not algae though.
The only sad thing was the treatment. All the articles said that switching lights off and water changes did no good and the only remedy was some stuff called "ERYTHROMYCIN" whatever that is. It sounds worse than the green gunge. Anyway thats the stuff that kills it and it would appear to be harmless to plants, fish and the filter bacteria.
All I have to do now is find some of this stuff ?.
If I do I will let you know the results.
Regards
Mike...................