lovely shots Sally, i love the Rainbows (otherwise known as Blue Rainbows) they were one of the types i was considering when i got my Rainbows.
that's a lovely little set-up you got there
Do you have any spare heaters? A 300W in a 180-litre would scare me a bit, just in case it gets "stuck on", but that's me being ultra paranoid really!
I have a 300W in my 450 litre and 200W in my 300 litre's