Teela,
Perhaps you are trying too hard.
Our house came with an above ground pool but I couldn't be bothered maintaining it. When our cats were small we worried they'd fall in so we got one of those black plastic covers for the pool. After a few months it had water on top and this makes a very nice (and large) pond. We now get 20+ male Peron's tree frogs calling from in, on and around it every night from around September to March. I expect we're only a few weeks away from having the "pool" full of tadpoles, too.
Greg,
It is a different frog and is probably closer in terms of colour to life. I'm still in the process of tuning the white balance with the flash. (I found my old gray card (Kodak Neutral Test Card) yesterday so I'm not that far away from getting it right.)