Red bump on Randall Goby

[5280Reefer]

1st time I ever see this, he did not have it when I got him. No QT atm and parameters are as follows ph 7.98-8.1 ammo 0 Nitrite 0 Nitrate 8ppm phos.06

 

[Big G]

While all red sores should be view with suspicion, that looks more like the goby has been digging under those new rocks and scuffed its head area pushing sand out to make a hangout. That being said, you really want to keep an eye on the area. It will be hard to see with such light colored skin, but watching for a white filmy area around and on that sore would indicate a bacterial infection has started. Do you have any antibiotics like Kanaplex, Furan2, Triple Sulfa (Sulfaplex), or NFG on hand?

 

[5280Reefer]

No medication right now but I will keep a close eye

 

[Big G]

No medication right now but I will keep a close eye

If the spot does develop into a bacterial infection you need to move quickly. Those types of infections can go sideways incredibly fast. Highly recommend at least keeping Kanaplex and Sulfaplex on hand at a minimum. Best of luck with your fish.