Installing overflow rain barrel #3

I bought 3 barrels the other day and made rain barrels out of them.  I installed the first barrel under my deck and the second one in the corner of my yard behind the trellis.  Barrel #2 is going to feed barrel #3, so it had to be installed first. 

Overflow barrel #3 is being placed next to my shed.  I plan on using it to water the chickens and the ducks.  Below is a picture taking from overflow barrel #2 with barrel #3 in the distance.

Below is a picture of overflow barrel #2.  I connected a Y-valve to the hose bib.  One of the lines attached to it is connected to the rain barrel at the back of my house.  I documented how I set this up here.  The other connection goes to overflow barrel #3 by the shed. 

Here's a picture of overflow barrel #3.  The connection I'm using here is only temporary.  This barrel is a lot lower than my other barrels.  I have to put a float valve on it to keep it from overflowing.  I've ordered one from Amazon, but it hasn't gotten here yet.  I hooked it up this way so I could fill it.

Those 5-gallon buckets are going to go away once the barrel is full.

This barrel won't be fed by a downspout, but some runoff from the roof will probably end up in it.

To deal with roof runoff I drilled holes in the lid and added some mesh screen.

It isn't evident from the picture at the top of this post, but this barrel is a lot lower than overflow barrel #2.  I opened the valve on barrel #2 to fill barrel #3 and went about doing stuff in my yard.  I came back later and found barrel #2 empty and barrel #3 filled to the very top.

I didn't think that this barrel was that much lower, but I guess it is.