This is amazing. I've never used a forum for anything before and want to thank you all for the time you've taken to answer my questions, and for not making me feel stupid!
I'm still a little confused about the bulbs (we have three and counting!) but I'll post again after I've taken out the substrate, reorganised the viv and re-read the posts. We have a digital thermometer which we've moved around the viv to make sure there is a heat gradient. We didn't attach the heat mat because once we put the moss in the temp at the top got to 25c and at the bottom was 18c ish.
We live in a small, old and cold house so need some heat for the viv as the ambient temp in my sons room is 15-18c (no oil/central or electric heating) just jumpers, water bottles and wood burner downstairs!
I'll post some pictures as soon as I learn how to!
Thanks again. Jacqueline (Ruben's mum)