I've not seen iron destroy pumps but then the nearest I have ever lived to Texas is Oklahoma. I think there is sone other problem such as cycling of the pump. If thats the case I'd suggest that you consider installing a Cycle Stop Valve http://www.cyclestopvalves.com. Cycling and inproper installation distroys pumps quicker than anything. Be sure you contract a state licenesed pump installer. I would also consider contracting a NGWA Certified Contractor.