When I had a smaller pump (shallow well) and small tank my water pressure was great. When I had to replace everything the person installing the system put a bigger pump and a huge pressure tank. It is the size of a 50 gal water heater. I replaced everything. Ever since then my water pressure is terrible. My sprinkler will not even go around. The pressure gage says the pressure is OK. There is plenty of water. I can't figure it out. Do you think the tank is to big?