In need of some assistance,
Have two female turtles that are just about six years old.
Have had since hatchlings and have cohabbed forever.
Living in a 75g tank that they have outgrown and I am looking to upgrade to 125 with above rank basking spot but am concerned and need assistance.
A month of two ago the smaller turtle started biting at the tank silicone and then at the water heater and now she is biting the feet of the bigger turtle and trying to bite her face and neck even when basking. I've had to remove the smaller turtle on a few occasions now for time out in the bathtub.
I am really concerned about spending $1000+ on a brand new set up (I am not well off) and having the aggression issue continue. I live in a very small apartment and have other pets and literally have no space. I wanted to separate via a top and bottom tank on a metal stand but I have found I can't find a sufficiently sized tank that will fit on the bottom and accommodate all the lights. Also, the electrical in my building is very old and I already have to turn things off to vacuum and am concerned about its ability to accommodate two extra lights, extra water heater, and extra filter...
I am wondering if anyone has any insight on whether aggression would be likely to continue or any possible solution. I am very stressed about this situation and don't know what the best course of action is.
Any advice appreciated.

