After my first dose of "Algae Cure" (2 weeks ago) I practically striped the tank down. I only left about 20% of the water and gravel vacumed all the way down. The fine muck was still thick when I stopped but time constraints made it impossible to totally empty the tank.

After I refilled and conditioned the tank I added the second dose of Algae Cure.

One thing I noticed that was very strange was the state of the filter material. It was pristine . Even when I rinsed it the rinsing water was almost clear. I figured my filter material mustn't be fine enough to trap the fine particles of debris and algae which just keep circulating through the tank until they settled at the bottom.

I added some new filter material and noticed that after 12 hours I could see it turning brownish/green, it must be collecting some of the finer particles.

The tank is almost clear now - still slightly cloudy with a greenish tinge but at least I can see my fish! I'll let you know how it's going in another fortnight.

Have to admit it's getting better, a little better all the time.