[simonx98]

HI there,

I have two waterbutts - an 250L amphora urn style from Garantia (impossible to access the inside of this one) and a regular Ward 210L from B&Q. I want to connect them together at the bottom so I only need a tap the urn style, with the other sitting behind it, water levels rising and falling together.

On the urn there is a screw-in drainage plug socket I can use, on the regular one I can take out the tap and use that socket, they have the same dimensions so guessing it must be a standard size - apx. a 9cm circumference, there is eventually a question on this!!

I bought a connector kit from B&Q (see first picture), but this is designed for new holes, I cut off the flange (intended for inside) on them, screwed into both waterbutts, but only a couple of turns for the urn - which increases my concern that without washers/flanges they are going to leak with all the pressure they will have to bear.

I think I need to buy something better suited to the job, such as the brass ones in second picture, however there is a variety of size options, any advice on what size required for these connectors? Any other advice also would be much appreciated.

[Blewit]

I joined two blue plastic barrels together so they balance. Used two normal plastic barrel taps and a length of hosepipe between just pushed onto the tap. It's lasted 11 years so far without any problems.

[simonx98]

Have gone for these and they fit a treat:
https://www.amazon.co.uk/Water-Butt-Connector-Pipe-Link/dp/B001DYWUNW?th=1&tag=diynotcom-21
A pity B&Q don't sell them, since my water butt is the same brand (Ward) and I bought there but had to buy the other connector kit which I had to hack, and then decide against!

[Subversive_plot]

I'm a bit late to the party . . .

You can easily connect two containers together without any drilling etc. 

Simply use a section of flexible hose (or tubing) to make a siphon. The tubing length should equal the vertical length from the top to the bottom of both water butt, plus any horizontal distance between them. To each end of the tubing, attach weight to the tubing (band clamps holding something like very large hex  nuts onto the tubing would work).  The weight holds the tubing on the bottom of each water butt.

With each water butt full, fill the siphon tubing with water, then place one end of the siphon into each water butt. As long as you don't run the siphon dry, the two water butts will be hydraulically connected, and in equilibrium.