If you're not using cards, you're not conserving your mana as much as possible. (5/6 cards "conserve mana", by lowering the required heal output, making the fight shorter or straight up lowering mana costs) You can always draw a card after using Aspected Benefic/Exalted Detriment without really lowering your Heals per second. You should also use Refresh asap, so you're able to use it twice during a longer battle.