These are my little guys

[The triplets]

I have had them for a month and they seem pretty happy here. They originally had a fake moss on the ground but I recently removed it when they where avoiding it. They where a little bruised up when I got them (gills are short on all, the middle one seems to have had longer gills at one point) and I was wondering if there is a way to help the gills grow back? They don’t fight eachother, are separated during feeding and live in a 60 gallon tank together.
If anyone has tips on helping axolotls regenerate gill could you tell me?

 

[Egghead]

I think high quality water and low oxygen usually promotes gill growth

 

[The triplets]

Thank you so much I will be trying that.