GERD sucks. My best advise is to brew what you like to drink and then drink in small amounts. Overfilling the stomach is a major cause of discomfort. Better to sip a bit and be in less pain than to guzzle it down and feel miserable later.
And I agree that water might be a problem with lighter beer. It's a common problem in certain parts of the country. Also, as a matter of course, watch out for treated water from your city. Chloramines are often added and can trouble a beer after fermentation. If you are brewing lighter beers, try RO water. Remember to ferment on the low side, and for as long as need be to ferment completely.
Sometimes the sun shines in, and I close the blinds, cause I can't stand to see the light of day. I have no use for pain, but I don't mind the rain, cause I can stay inside and hear the sound.
Today I look right down, right down to the ground, there's nothing in between to break by fall. I'm blue for you, and I don't know what to do.