if you didn't know, throwing sugar into your dwc is akin to throwing bloody meat into a phirana infested amazon river.
plants will dig it, sure.
bacteria will dig it, absolutely.
every rez contains both good & bad bacteria, you'll be feeding them both.
i have run a diluted (1 to 2 tsp per gallon) mix of blackstrap molases in my rez ...but i have come to see that as a risk.
when i have put carbs in the rez, usually toward the mid to end of flower, i monitored everything very closely & changed out in three days.
i am interested to see what others think.
~karma