I have an Arctic Spas 1400 liter (370 gallons or so) hot tub. I use the 3 step bromine method.

What I've been doing is adding a bit of bleach to the tub after every time I use it. Normally me and my girlfriend are in it every night for about 15 minutes or so. I usually add a bit of bleach right afterwards. Then about once a week I'll add quite a bit of bleach to bring it up to 15 ppm.

Is this what I should be doing, or should I only add bleach after a soak if the bromine levels are quite low?

That's pretty much the same routine I use to do.

How are you testing?

On my weekly shock I would always use spa perfect enzymes and sea clear. Alway got more waste out of the tub that way.

If you use the tub at least 3 to 4 times a week you should consider dichlor/bleach. I am much happier with it. Water smells better and I don't get near as much waste when I oxidize.