Honestly, once a week is pretty good! What matters most to readers is really that you update regularly, most are understanding that not everyone can spend too much time writing. Also, it's important to go at a pace that doesn't cause you too much stress.
Some of the people updating multiple times a week probably have some chapters ready to go and I would recommend building up a buffer just in case. But yeah, just update regularly, find a pace that works for you, and communicate with your readers when you need to take a break.