I'm trying to hunt for the trident but obtaining high quantities of blood runes is becoming an issue. I tried my hand at zulrah but had zero pure ess drops in 50 kills. Barrows gave me zero blood rune drops in 30 chests.. Does ceberus give a decent amount of p ess drops or am I going to have to mine it myself? How did you other ironmen get your blood runes?
Keep at it with Zulrah, you're bound to get the 1,500 noted pure essence drop eventually. I believe Cerberus drops 300 noted pure essence. Gargoyles drop 150 noted pure essence and skeletal wyverns drop 250 noted pure essence.
Runecrafting them can be pretty time-consuming, especially if you don't have a good batch of pure essence. I'd keep going with barrows and hope for the best. Best of luck.