Yesterday I added a 20gal sump to my octo system and this morning I didn't see her. This afternoon after not seeing her in the morning I went looking ( her favorite spot is in the very back of the tank under a piece of live rock ) she was in her den ( I have to use a mirror to see her ) she was not looking too good. She didn't change colour or move other than breathing. I tried prodding her with a feeding stick and she grabbed on and I dragged her out of her den. Long story short after about 45 min I got her up to the top of the tank. I was sure she didn't have much time left. She had been very limp the whole time no fight other than sucking onto things she came into contact with. As a last effort (suspecting something in the water) I filled a bucket with water from one of my other tanks and gently moved her to the bucket. within about 15 min she was starting to come around and did a little colour change after 45 min she had some strength back and was starting to move. She is now in a critter keeper in another tank and looking better. All the rest of the inhabitants of her tank all look fine water tests all look good I suspect something toxic in the sump or hose. The sump and all hardware is brand new and well rinsed. The only things in the sump are water and macro algae. I have added three large sacs of carbon directly into the tank in areas of good flow. I need to know if anyone knows a way to test for toxic chemicals in the system or knows another good way to remove them.