Guinea pigs need hay everyday to keep themself healthy and if they don't get it everyday it could cause problems for their digestive system so you are correct in giving it everyday. I don't think you can give a guinea pig too much hay but if you do give them too much hay they may waste it by using it as bedding or soil it.A routine is good by giving a handful in the morning and later in the afternoon or night.
Just remember to give Fresh water and greens everyday as well as dry food. Hope I helped
Just remember to give Fresh water and greens everyday as well as dry food. Hope I helped