And then there was light!!! I can see it now!
Thanks Maggie, the middle is approx 14" deep and despite their best efforts (i.e. Riding the rapids on a couple of occasions) none of the fish currently reside in there! (I took your advice from the BBC website and decided on top and bottom only for fish.)
Since taking the piccie, I've added some more plants to all three sections, a couple of hanging baskets to cover up the unsightly lime staines on the wall to the right and an urn at the top as the water outlet from the filter (top right) I think I mentioned this previously again on the BBC.
I'm still having problems with flooding and as you can see, with the bottom section being lower than the rest of the area when the water in the bottom does get too high it has no-where to go to. Next (and probably final) job will be the overflow which I have talked about, and put off doing, since approx July last year!
Did you decide on a personal reg?
Tony