Have had a recycling tank for 6 months, and working well. Except, flushing water is yellowish, and if toilet not used for a few weeks, turning blackish. There is a fair bit of tree pollen and birch seeds bung up the rainwater downpipe gulleys, and also in the filter in the tank. But how to keep the water fresh? Does it need something like potassium permanganate in the tank to keep it sweet or dosing toilet with bleach. Anybody else have experience of this?

We had an original Victorian underground rainwater collecting tank at our last house. The roof water went through a two stage sand filter bed before going into the tank. The water was always crystal clear. We only used it to water the garden but it was interesting that the Victorians had it all sussed over a hundred years ago.

I wondered how long it would be before someone mentioned 'What the Romans did for us'.

I have had mine for 6 years, it did go very worryingly smelly after a few months. I added half a cup of cider vinegar after advice on here.

Fine ever since, if lots of leaves get in it can discolour but I strain them out at the bottom of the down pipes .