Steve - The wood doesn't seem to be causing the main problem. The stringy algae is only on the plants, not the wood. The BBA and Staghorn however is only on the wood, but the wood wouldn't cause that would it? There's now some dark hair algae on the edges of the old Staurogyne leaves.
Mike - The the thing is the tank should be mature by now, surely. I had normal diatoms for quite a while during startup, then everything cleared within a couple of days and it was near perfect. Then suddenly I had this outbreak, which is still growing incredibly quickly. The algae is growing about half an inch to an inch per day. I'm down to 11w of light too now, and the tank looks very dark. Could be because of the red bulb though.
I'm still at 2bps CO2 which should be way way too much, yet the BBA and Staghorn is still accelerating. The Amano's seem to hide all day and night too - They don't appear to eat any algae at all, and as I've already said the Otos were gassed.
The spraybar is great for distribution - the CO2 bubbles are easily flowing round the whole tank and are being blasted directly at the BBA on the wood with no improvement. Anyway, even with the level of Excel I'm dosing I shouldn't even need to add any CO2!