Just ordered more replacement heads for the nova. Ordered a couple more 3.5 Nova's and 2 replacement tanks for the ones that went leaky on me. I know, I know....I should rebuild my coils. I just don't want to right now. That silica is slippery and I know I need glasses for close up work. Cheaper to just buy the heads. Mine are still going strong, still only have the two that bit the dust. I just like to have that backup piece of mind.
GT is right Robin. Replacement coils are cheap so you shouldn't have to feel pressured to rebuild your own. I do it only because I make them better than what came with the Vivi Nova's. But if you're happy with how yours are working then I see no reason to change or worry about it. Enjoy!

