I recently installed a new variable speed pump so I could have constant pressure in my house.

I replaced a very large Welltrol tank with a tiny one since my plumber said that was all I needed. The problem is the pump is shutting off 2-3 times a week because of a low pressure condition and taking about 15-20 minutes to reset. I have a very small utility room and can't fit a big water storage tank. Could I accomplish the same thing by just upsizing the Welltrol tank? I really only need about another 30 gallons available to prevent the problem. My Well has a rate of about 3.5 Gallons and is only 150 feet deep.