I was having major problems with BBA recently on my anubias plants, then spreading to the tank walls and rocks, and found that this method really worked. Thought I'd post it up here as I've seen lots of people complaining about this type of algae and it can be difficult to find algae-eating fish that will a) actually eat it and b) be able to withstand the current in a hillstream tank. I'd heard people mention overdosing with Flourish excel but that stuff is pretty expensive over here in NZ so here's how to kill the algae with one dose.
So here's what I did:
Remove 50% of the tank water into a large container, put all the fish in there with it (and a heater/air pump if this is going to take you a while.)
Remove the rest of the water via gravel siphon, and discard.
Measure out whatever dosage of excel you need for the whole tank (5ml for every 40 litres) and put into a clean, small spray bottle (you can get them for around $2 in the garden section in shops). Top up the bottle to about half full using clean water.
Liberally spray the glass, driftwood, rocks etc with this concentrated mix. Drench everything in the mix and leave it there for maybe half an hour, then scrub the more durable objects like driftwood.
Then I just refilled the tank again using the old water and clean new water. My fish all seemed fine (my ghp rasboras actually started breeding the next day but that could be coincidence!
) The algae had all completely died /been eaten away by loaches within 3 days, woohoo!