I have a yard hydrant about 40 ft away from a barn. Every winter its the
same fight with garden hoses freezing up. I need to fill a water tank in
the barn for a few horses about every 2 days.

This hydrant is uphill from the barn, and there is a pole right near
that hydrant. My thought is to run a piece of stainless steel cable from
that pole to the barn. Then attach the hose to the cable with wire-ties.

The hose then runs into the barn, and to the stock tank. It will slope
downhill all the way, so as soon as the tank is filled, I will remove
the female hose end from the hydrant and the water inside the hose will
drain into the tank, so the hose can not freeze.

However, I must make sure there are no sags in the hose, where water
will collect and freeze.

The other problem I see, is that where the hose enters the barn wall,
rain water will run down the outside of the hose and into the barn. I
cant put a drip loop in the hose, because that spot would freeze in
winter. I'm thinking I'll have to put some silicone caulk where it
enters the wall.

Anyhow, I thought I'd ask if anyone on here has tried something like
this? I am also thinking of using some other material, instead of a
hose. I'm aware that a hose exposed to sunlight wont last real long, so
I could also use that black polyurathane pipe that's made for
underground use, or some of that PEX pipe. That Poly pipe is kind of
stiff, so I dont know if I could get all the sags out of it. And being
black, how well will that pipe hold up in sunlight?

So, what about that PEX pipe? How does that hold up in sunlight? I've
never used it, but have felt it in stores, and it seems rather stiff
also. I know it needs a special tool to attach fittings, and I will need
to attach a fitting on the one end by the hydrant, so I can run a short
hose from that pipe to the hydrant. I'm not too worried about needing
that tool, because I can get the hardware store to clamp that fitting
for a buck, before I hang the pipe.

Anyhow, what would be the best material to use? Poly pipe, PEX pipe, or
just a garden hose?