Help on high ph In minnow tank

Just looking for some tips . Just set up a minnow tank using a plastic barrel,filter and bubbler and am using tetra aquarium additives. After a couple treatments my ph ,alkalininity and hardness levels are still high according to test strips. Other levels are fine. Is there something else I can use to lower these levels a little faster ? I have minnows in the tank and they seem to be doing fine. I know from having a swimming pool in the past I always had ph problems with my water, I always had to use muratic acid to get it down so I know it's gonna be tough. I'll appreciate any help.

Amazon.com: aquarium ph down

Thanks canebreaker ! I'll give that stuff a try

I guess I've been lucky. Never check my water. Just drain about 1/2 once every week or 2, refill and add enough bait saver to treat the new water. The only problem I've ever had is keeping the raccoons out of the tank.