Who Gives A Fish Forums

What's the best treatment for a new tank with fin rot? Got a 20 gallon with some guppies showing signs, and I'm not sure what to grab from the store.

I've had good luck with Melafix for mild cases. Just make sure your water params are solid, 0 ammonia, 0 nitrite, and keep up with water changes. How often are you changing water right now?

Fablet1 wrote: ↑Thu Jul 24, 2025 5:46 pm What's the best treatment for a new tank with fin rot? Got a 20 gallon with some guppies showing signs, and I'm not sure what to grab from the store.

If it's early stage, salt baths can work wonders. I use 1 tbsp per 5 gallons, but only for a few days. Watch how they react.

Fin rot can be stressful for both you and the fish. I'd second the Melafix suggestion, but also check if your filter flow is too strong. Sometimes fin damage starts from physical stress.

For stubborn cases, Kanaplex is my go-to. It's a bit stronger but effective. Just be careful with invertebrates if you have any. What's your tank temp? Warmer water can help speed up healing.

Thanks for the tips, everyone. Gonna try Melafix first and keep an eye on the water changes. Appreciate the help!

Fablet1 wrote: ↑Thu Jul 24, 2025 8:28 pm Thanks for the tips, everyone. Gonna try Melafix first and keep an eye on the water changes. Appreciate the help!

No problem! Let us know how it goes. Guppies are tough little guys, they'll bounce back.

Also, if you're using tap water, double-check your conditioner. Some brands don't handle chloramines well, and that can mess with their slime coat.

I've seen fin rot clear up just with cleaner water and a bit of patience. Sometimes less is more if the fish aren't too far gone.

mikewoods wrote: ↑Thu Jul 24, 2025 9:15 pm Also, if you're using tap water, double-check your conditioner. Some brands don't handle chloramines well, and that can mess with their slime coat.

Good point. Seachem Prime is my favorite for that. Covers all the bases without overdoing it.