Stay away from the brown acid — and this guy’s Phish tickets.

A would-be scalper was arrested last week after the NYPD found him making counterfeit tickets to Phish’s upcoming New Year’s run at Madison Square Garden inside his Bronx apartment, police announced Tuesday.

Michael Pinero, 33, on Friday was “caught red-handed in the process of creating counterfeit Phish @ Madison Square Garden tickets. (C’mon, bro!),” the 20th precinct wrote on Facebook.

Cops began their investigation in October when an Upper West Side resident got scammed by bogus tickets. Plain-clothes officers arrested the middleman who allegedly sold the stubs.

This led them to Pinero’s Kingsbridge apartment, where he “was creating hundreds of fake tickets,” they said.

All of his computer equipment was seized.

Pinero was charged with second-degree possession of a forged instrument, a felony, and other charges, public records show.

He was arraigned in Manhattan Supreme Court Monday, where he pleaded not guilty and was released without bail.

The cops — apparently Phish fans themselves — wrote that “on behalf of Mr. Pinero’s victims, we can think of nothing more appropriate than this:”

“I can’t track you anymore
Detective work has sure become a bore
So tell me what you did with it
And stop this ****, give up yourself
Before they come knockin’…”

Those are lyrics from “Poor Heart,” off the rock band’s 1992 studio album “A Picture of Nectar.”

Pinero’s next court appearance is scheduled for February 27, 2020.