18 gauge irrigation wire for the size.
make sure you have checked at different times of the day....i.e morning, lunch, and midnight for consistency.
Actually, fescue is not very low maintenance at all. In fact, Zoysia and bermuda are much more low maintenance than any fescue. Most of the time the zoysia and bermudas will keep weeds since they are so thick. Survival of the fittest. A lot of times the fescue will loose out to weeds, or is very expensive to maintain compared to the warm season grasses.