Well ladies and gents, it has been a bumpy ride over which I have come so very close to packing it all in. Initially I struggled with green spot, then BBA, slow growth and the loss of many, many little glass yellow tetra fish (which at £10 a pop was a costly loss - and alas the distributor are unlikely to be getting any more of the beautiful, little critters).
Despite all that, I'm pleased to say that I stuck with it and finally figured out that with regular water changes (once weekly seems to do), daily ferts, not too many hours of light (and not too few) and a good,
constant supply of CO2 things really start heading in the right direction.
Here's the tank as it stands, it's not perfect I'll grant you and I just did a fairly heavy prune but the algae is subsiding, the HC is growing fiercely and maintaining the tank has become a little more manageable.
This planted aquaria lark is a LOT more work than I realized (no doubt due in part to my inexperience) but I have to admit, despite all the effort involved I do get a LOT of enjoyment from sitting in my study and watching the fish and shrimp swim amidst my own little green and pleasant 'scape.
(Edit: I should add that the fish died from jumping out the tank. They were very fast swimming and very jumpy and coupled with filling the tank to the rim most of the time meant I lost nearly all of them.)