Doc's tip on 'fizzing' is good - if it isn't fizzing at all after a minute or five, that's an easy sign; I immediately switch to new copper wire hangers as my first action. If it still isn't fizzing, you probably haven't got it clean and you're going to see it good in spots and nothing elsewhere. If it's got acne, it's probably crud in your mix. If everything else is good, you probably need to pull all the bits out and try one at a time, not ten :-)
One other thing I do every few months is to wire-wheel the anodes to get them shiny and new again. Don't just take them out and dump in a drawer or whatever. Make sure you rinse them off and keep them clean too. Of course, do NOT leave them lying in the mix for days.
Wire-wheel it, degrease it, rinse it. Don't overdo the hydrochloric etc. a 1/2 hour or so is probably enough (depending on state), so keep an eye on things. and make sure you rinse it all off and have it utterly clean before you drop it in... and keep your mits off it!!! when you pull it out, don't touch anything. Just hang 'em up and walk away. Especially zinc... you grab at it (it's hard to fight the tempation!) and a lovely black smudge appears from your finger oils and you'll howl...
Did I mention CLEAN? ...