White hole in the side of my Molly

[SavannaNeniska]

One of my Dalmatian mollies seems to have a large white hole in its side. It’s the only fish in the tank with this symptom. The tank has 10 mollies, 10 corydoras, and 5 bristle nose pleco. It is a 70 gallons tank. This fish is a baby that was born and raised in my tank so likely not a disease from a pet store. No recent additions to the tank. Wondering what it could possibly be. 
ammonia - 0
pH- between 7-7.5

Nitrite - 0 ppm

nitrate - about 20 ppm

KH - between 40-80 ppm

and GH - 180 ppm  

water temperate is 79°f

I do a 25-50% water change every 1-2 weeks 

Edited April 22, 2023 by SavannaNeniska

[TheSwissAquarist]

Have you tried adding aquarium salt? I would also recommend Ich-X as it looks like a superficial problem.

Correct me if I’m wrong @Colu

[Colu]

It's difficult to tell from your your picture it could be a prolapse from the vent  correct me if am wrong if it is Epsom salt baths 1 table spoon for 1 gallon for no more than 15 minutes for 5 days as Epsom salt acts as a muscle relaxant to help your fish reabsorb the prolapse @SavannaNeniska

[SavannaNeniska]

@Colu

I’ve never heard of that before but when I googled it, it doesn’t seem like it. This hole/raised lump is coming from higher up on her stomach on the side of her body. If I try to epsom salt salt bath, will it do damage to her if it isn’t a prolapse? 
thanks! 

[Colu]

If it's not a prolapse what is would do if you can is quarantine and treat with aquarium salt 1 table spoon for 3 gallons as it could be a fluid filled lump and the salt will help reduce the fluid buildup @SavannaNeniska