Who Gives A Fish Forums

I've heard about the vinegar test for checking if rocks are aquarium safe, but all I've got is apple cider vinegar. Will it work the same as white vinegar? My tank's a 20 gallon with a pair of Angelfish, and I don't wanna mess with their setup if it's sketchy.

Apple cider vinegar has a lower acidity than white vinegar, so it might not be as effective. I'd recommend sticking to white vinegar if you can. What kind of rocks are you testing? Some are more porous than others.

I've used apple cider vinegar before in a pinch, and it worked fine for me. Just make sure you rinse the rock really well after. My Betta didn't seem to mind, but I'd still be cautious with sensitive fish like your Angelfish.

Why not just chuck the rock in and see what happens? Live dangerously. Kidding, kinda. But seriously, if it fizzes, it's bad news. If not, you're probably good. My Gouramis survived my sketchy rock phase, so there's that.

Apple cider vinegar should work, but like Lynxor said, it's not as strong. I'd let it sit longer to be safe. My 55 gallon has lava rocks I tested with white vinegar, and they've been fine for years.

I'd play it safe and grab some white vinegar. It's cheap and reliable. Your Angelfish will thank you. My tank's got driftwood and slate, and I always test with white vinegar just to be sure.

Lynxor wrote: ↑Mon Apr 21, 2025 5:54 pm Apple cider vinegar has a lower acidity than white vinegar, so it might not be as effective. I'd recommend sticking to white vinegar if you can. What kind of rocks are you testing? Some are more porous than others.

Thanks for the heads up. It's just some river rocks I picked up. I'll grab some white vinegar to be safe.

River rocks are usually safe, but testing never hurts. Better to be cautious than deal with a crashed tank. My Corydoras had issues once from a bad rock, so I'm extra careful now.

Good call on the river rocks. They're pretty inert most of the time. My community tank has a few, and they've been great. Just make sure they're clean before adding them.

daxton9 wrote: ↑Tue Apr 22, 2025 12:06 am Good call on the river rocks. They're pretty inert most of the time. My community tank has a few, and they've been great. Just make sure they're clean before adding them.

Yeah, or just toss 'em in and blame the fish if things go south. Kidding again. Mostly.