Betta with lump under gills/chin.

[Eupterus]

Not an emergency...

I have a female betta who last was in my 30 gal planted with two plecos. No known issues in this tank. She has a reddish lump under her gills around the "chin" area for lack of better terms. She continues to swim around normally and eat.
She's been in 1 gal being treated with salt for several days now. Anyone have a clue what this could be?.

[ScottFish]

Keep an eye on her. Have the plecos been pestering her? Swimming and eating normally is a good sign.

[Callen]

IMO Don't treat with salt. Use Epsom salts (pure) instead...this will draw out any fluid and may help the lump go down. Dissolve 1-2 tsp in some tank water and add to the tank slowly.

Not saying this is a cure because we don't know what it is but it won't hurt her and it's a gentle treatment.

Salt at long periods can cause kidney failure.

[freshfish]

Any chance you could post up a picture? Hard to say if it might be an infection, tumor, parasite, wound, etc- and the best way to treat can depend on what's actually causing the problem.

I'm not going to disagree that long-term salt use can cause kidney issues, but I've personally found salt to be a very effective short-term treatment with many issues especially common to bettas...

[Diana]

What species of Pleco?
What size is their mouth?
What size is the red area? Is it a flat or very slightly raised, more like irritation?
Really odd spot, but some species of Loricariad and other sucker mouthed fish will latch onto the sides (not often the head or chin) and suck (or rasp) the slime coat off fish. I have heard of this behavior with Common Plecos, Chinese Algae eaters, and one report of Otocinclus. The usual victims are slow moving, flat sided fish like Gouramis, Angels, Discus and Goldfish.

An actual swelling is not so likely to be caused by the Plecos.

[Eupterus]

If my camera equipment didn't get soaked in a water leak, I'd love to take pictures.

The plecos are a pair of medium sized bristlenose types, species unknown.
I haven't heard much about bristlenose engaging in the sort of sucking behavior you describe.

Reddish area is raised. I've come to the conclusion that the cause of this is probably moving the betta around too frequently. I had in her in the 55 gal, then I needed the tank, I put her into the 40, needed that tank and then she went into the 30 gal.

[freshfish]

Any change in how she's doing?

What's the temp in her QT tank?

[Eupterus]

About the same. Temp is probably slightly above room temps as I put in a tiny 10 watt heater.

[Callen]

I've come to the conclusion that the cause of this is probably moving the betta around too frequently.

If this is from an injury then the Epsom salts will help. It also helps prevent secondary infections as it draws out the fluid.