Cleaning a dirty used tank

[raphgiroux]

Hello there, I just bought a 4 yo tank, there is literally thousands of feather duster tubes in my corner overflow box, onto AND into the pvc pipes. How can I wash them off safely for my critters?!? Got a couple yards of PVC plumbings lolll

 

[ZoWhat]

Straight vinegar.... be prepared to have your eyes and nose water like crazy