Hi, I am new to this site. I live in a 1100 sq. ft. ranch and currently have a pressure tank which I suspect is as old as the house (a little over 60 years) if that is possible.(I don't kow low long they are supposed to last). I am only here 8 years and the guy who balances the tank for me had been doing it for the previous owner. I cal him every 6 to 9 months. Lately I notice a more significant drop in water pressure when I use the outdoor spigot to water the garden. So it's probably getting to be time to replace the old tank. I'd rather ask you all this as disinterested parties. How do I know what size tank I will need? Is the guy who's been balancing the old tank the person to replace it? Are there tank replacement specialists? I appreciate any info you can impart.