Angelfish, watertanks and possum poo

Hi all. I have a large colourbond, unused watertank next to the house that receives run off from the roof. I live in the Blue mountains NSW, so I am not so worried about polutants. Heaps of broken down leaves/gumnuts etc get washed down into the tank, I am not that worried about that either - its probably good for the fish. However we have possums by the score storming accross the roof at night - as the neighbours leave out food for them and they eat it on our roof. I am sure their "poo" is left behind to wash into the tank when it rains. It is certainly all over the ground at the front door every morning.

I would REALLY like to use the water from the water tank in my fish room. Would you risk it? Would you filter/treat the water in some way? or am I being too precious about it? The main inhabitants of my tanks are freshwater Angelfish (breeders). What are your thoughts?

I'm pretty sure in the wild a certain amount of animal poop lands in fish water and does no harm, however I think I'd be inclined to filter it through carbon before going in your tank :)

agree with merrilyn you will have lovely soft acidic water , an inline carbon filter will take care of any nasties

Thanks for the replies, that's good news! Actually "scores of possums" is probably an exaggeration, but it can sound like it some nights. I will look into a good carbon filter.