i have a reef type octopus from karratha W.A. he has inked a couple of time in the tank and i have left it for a couple of days i dont think its that bad for the water quality it disapers in second and has never affected any of the corals i have in the tank
my tanks is 5ft bayview just over 2ft deep and 1.5 at its widest the tank has been running about 4 months and had only about 4 water changes
i have only had him escape 1 time when i left the lid off for about 3 days my lid is just eggcreate he wont crawl through it because as soon as he hit gravity i imagine the eggcreat is to shrarpe for him to pull him self over u could also use velcro around the lip of the tank and or use gutter gurad comeing up from the sides of the tank as the ocy cant grip the small mesh if u have anymore questions im sure i can help also i have some pics but dont have time to post them now thier just of me hand feeding the occy and holding him in my hand
also they dont like red one time my mate walked out side to look at the tank wearing a red jumper the occy inked and my mate told me 30seconds later and there was no trace of ink