Vetty
Lost and happy geek!
give your regulars notice about it.
Exactly what I do - put prices up from 1st Feb but tell regulars that their prices increase from 1st April.... They get plenty of time to get used to the idea and appreciate that they are paying less for 3 months than any new clients.
Btw, I charge £35 for a full set and £25 for a 2 week rebalance and those prices are going up this year. Don't undersell yourselves.