Hi Folks My 300ltr tank had a serious BBA problem for many months which resisted all my tweaks, potions and changes until the point when the CO2 drop checker reached yellow and I nearly nuked all the fish one weekend. After that I decided BBA was far better than a fishless tank. So I wound back the CO2 until the drop checker turned a nice grass green colour (PH 6.7ish) and introduced 3 siamese algae eaters. That was about 3 months ago and hey the BBA is now in severe decline! Hardly any cover the bogwood, filter inlets, glass etc. Don't really care wether it was reduced CO2 or the algae eaters, but it's working for me.