RI in my baby spur thighed tort

[Loagsmum]

Hello, this is my first time here as I am a little worried about my small one, s/he is 8 months and we have had him for 5 weeks and he is fed on weeds, crispy mix with a little watercress. His substrate is tortoise life med and he has a full spec Arcadia lamp (warm side 90-95)
He is eating and toileting as normal but has been squeaking and today had a bubble from his nose, he saw the vet 2 weeks ago for an initial check over that seemed normal and so he went back today the vet has said he seemed ok but as I saw a bubble has given us antibiotics
What else can I do to help this?