hmmm if the container you want to fill with water is lower than the trough, you could siphon it out?? (I've never done this so can't give any practical advise).
Ah ha, the siphoning trick! I used to do that when changing the water in the fish tank. I usually ended up with a mouthful of aquarium water as part of the process, but it does work, albeit rather slowly.
how does the water get into your trough? If it goes through a plastic pipe the just cut into the pipe before it goes into the trough and put a "T" fitting in with a length of hose/pipe and a tap on the end.
The water trough has a ball cock in an enclosed section.
The reason for soaking is because pony has RAO and had mild laminitis for the first time this year (also is on Prascend for Cushings). So, haylage is good for the RAO but bad for the laminitis! She lives out 24/7 and I am currently trying to reduce her weight for health reasons.
There are no buildings other than the field shelter on the far side of the field and I doubt the field owner would agree to a tap being installed but that is an option worth looking in to.