Electric Fence... how high

I am putting up an electric fence to keep horses on one side of the 40 acres that I have access to. There are 3 horses total with two being a Shetland/Quarter cross (ages 10 adn 2) and the third being a Quarter horse (age 4).

The two year old filly is a very curious and has ran through just the wire that we had strung, but it was not electrified. I think she was used to going on the otherside without having a fence there.

We want to run 1 wire so that it would be easier to maintain, due to grass. However, how high or low should this 1 wire be? I am kinda working off of resources that are already provided (where a fence used to be). I don't have much funding to go purchase a bunch of poly tape or new post and etc... All I have is wire, white security tape (to tie on the fence to make it more visible), connectors, and t-posts. All we have is enough wire for 1 strand.

Suggestions please. We already have the posts driven and are ready to run the wire, except we are still trying to figure out how to get it ran to the fence charger.

Well I have an electric fence for my horses, and believe me, once they find out its electrified, than they wont touch it again. In my large pasture I have four strands of wire and in my smaller one I have only two. If there is only one wire than I would suggest putting it about two and a half to three feet high, depending if your horses will be able to get underneath it or not or if they can jump it. But if they find out that it is electrified than they shouldnt go under or over it, atleast my horses are like that anyway.

I have mine 3 ft off the ground, but my guys are 18 hands. I have mine between their chest and knee. Just make sure you have the tape the whole run so they can see it. I would do like racer179 said about 2.5 ft off ground you want it low enough that if they are grazing up to it that it will hit low enough on the neck if they touch it they will back up and not run under it.

Just make sure that its not higher than the smallest horses back but not too low that they can jump it. It depends on the horse but usually once they learn that its electric they stay away from it. A 2 foot hight peice of bailing twine would keep my boy chucky in but 6 strands of rope going as high as my shoulder wont keep in my other boy banjo. But electric fences are a different story, all my horses keep away from that... well banjo has gotten threw it once or twice but that's it