Hi All,
I am on a Well and have a Wellmate Pressure Tank. Model WM25WB. It is a 86 gallon Fiberglass Bladder Tank, not a Diaphragm. Installed August 2010.
I have a farm, so I use a lot of water to irrigate the crops and provide water for the animals.
In December 2015 I started experiencing low water pressure for a couple of weeks until I woke up one morning and had no water at all.
I called a plumber and he discovered that the Relay Switch for the Pump was fried and that the Pressure Tank was water logged. He replaced the Relay Switch, Drained the Pressure Tank of water, and re-pressurized the Tank with air. He said that the Relay Switch was fried because it was constantly trying to run the Pump.
Now I am experiencing low water pressure again. So I drained the Tank and re-pressurized it.
I called Wellmate and they said that I either have a leak from the Air Valve on top or a leak from the Air Bladder. I sprayed soapy water on the Air Valve, but did not see any bubbles.
So, I am considering replacing the Pressure Tank
I have several questions.
Are Wellmate Pressure Tanks a good choice? I have heard complaints about them and also heard a rumor that they had a bad run of Tanks a few years ago. Is this true?
Which type of Tanks are better, Bladder or Diaphragm?
In general, do Pressure Tanks need maintenance and constant Re-Pressurizing like car tires? I looked online and could not find any Owners Manual, only an Installation Manual.
Which Brand of Pressure Tank do you recommend?
Which Brand do you NOT recommend?
I am partial to Fiberglass. I live in very wet climate and my Pressure Tank is in a very small un-ventilated room, so I am concerned about rust. But, I will consider a Metal Tank, if you don't think rust will be a issue.
I would love to hear all opinions. Need to make a decision soon
Thank You All

Well Mate makes a good tank, and are the ones I normally use. Definitely use a tank with a bladder. Fiberglass is my choice of tank material as well. I'd say the bladder is leaking in your tank, and with no air in the bladder the pressure switch will wear itself out fairly quickly, due to the short cycling of the pump. If you have sediment in your water, that will certainly shorten the life of a tank. The bladder is constantly being compressed and expanding with water usage and with the pump running, so it gets quite a workout. I'd expect about a 12 year life span of your tank, a couple years either way depending on your water quality.

My choice for tanks is Well-X-Trol 'Professional'. It is metal and carries a 7 yr. warranty. I don't think anyone else in the industry has stepped up yet to match their warranty; most others are 5 yr. It is a diaphragm tank. I do not prefer the fiberglass tanks with a bladder. My experience with them tends to be negative. In an industrial setting such as yours, the larger the tank, the more run time the pump receives which is good because the pump runs longer per cycle but less frequently overall. Larger tank= more money, but should pay off long term.