the warden skill Tidal Resonance (Reduces the mana cost of your next Heal over time spell by 30% whenever you criticaly hit with a water based ability), when it procs it has 1 min duration to disappear, so logicaly it during this 1 minute it should only disapear when i actualy use a heal over time spell, however its disapearing the moment you use any spell even if it wasnt a heal over time, which makes it useless in most cases because im not always using a heal over time spell after i crit, infact, i prefer not to.. since i have serendipity from sentinel i would use a long cast spell after crit..

conclusion: during the 1 min it shouldnt disapear by using any skill whatsoever, it should only disapear when you use a HoT..