Just thought I'd post a thought - if you were to start up a new tank using old gravel (say you have tahitian moon sand like me) you could easily start this up using the old gravel, and you'd not have to do much with nitrates. I say this because last winter, I emptied a bunch of my old gravel into a 5 gallon pail and set it outside on my porch. (7th story in an apartment building) and wouldn't you know it, but come spring the tree seeds are blowing around on the wind and some of them landed in my bucket (which I had forgotten about) and then I noticed there are little plants sprouting out of my gravel! I'm not helping them in any way, but there are definitely tiny trees growing in my bucket outside, taking nutrients from old fish poo and getting watered by the Seattle rain.
I guess this post has only to add an additional note to why you want to put a cover on your tank when you put it outside in the sun.
I like this idea, and maybe if I were thinking about it more would have come up with it on my own. I've been watching these trees grow for a while now...
Thanks Tom for starting some buzz.