You only need to use a few down pipes to fill one tank. Cut the...

You only need to use a few down pipes to fill one tank.

Cut the down pipe around 40 mm below the gutter, attack a rectangular to 90 mm round adapter.

Fit a 90 degree elbow, run some 90 mm storm water pipe under the eaves/gutters until they get to tank.

Here you run them into 1 or 2 tee pieces, and feed water into tank.

So simple, no need for "wet" pipes, no need to remember to flush stagnant water, EVER.

To put it more simples, a down pipe doesn't have to run vertically to the ground.

Run them horizontally to the eaves, until they meet at the tank.

Even whoever plumbed my tank up, I'm renting, knew enough to feed two down pipes into a Tee piece,

then into the tank.

I'd dare say, even with an empty tank, it wouldn't take long, or a lot of rain,

before water came out of the tank overflow.