New member here. I've been a longtime lurker who focused on absorbing as much information as I could before buying a cephalopod. Perhaps I will post a more in-depth journal entry later. For now, I am concerned about my new O. briareus' behavior. Some background: I set up a 125 acrylic aquarium with a 40 gallon sump. For now, I have an octopus protein skimmer running in it and plan to add a canister filter from another established aquarium. The octopus aquarium had used sand from a 3 year old established tank. The tank contains only 50lbs of marco rocks because I had initially only had a 55 gallon setup before upgrading to the 125. The tank was allowed to age for 3 months. When I received the octopus from Tom (pretty popular guy here), it seemed well. It had not inked. It was reasonably calm in appearance. All test readings were within acceptable range except the pH was lower than 7.8 (guessing from my API test kit). After 4 hours of acclimation, the O. briareus has been in my aquarium since yesterday morning. My current readings: Salinity: 1.026 pH: 8.0 (Plan to raise the pH to 8.3 slowly due to low shipping pH) Temp: 74F Ammonia: 0 Nitrite: 0 Nitrate: 5-10 Hardness: 13 dKH (a little high) Now the octopus' behavior is concerning me. He seems to be fidgetting a lot. He curls his tentacles up (not corkscrewing) and seems to rub at himself. He shifts a bit when he sits. He inked once when put into the tank but it wasn't much. It was very thick. I've never seen an O. briareus in person before so I am unsure about their usual behavioral patterns. I'm used to seeing octopus sit still with only their syphon moving. I did notice that when he was acclimating, he had shed a bunch of suckers. He's ceased rubbing at himself from what I can see but the fidgetting is making me crazy with worry. My mind automatically leaps to heavy metal poisoning. I use RO/DI water and though the tank is used, the owner swears he did not use copper. I worry about his memory because he hadn't used the aquarium for 12 years. The tank does not have any measurable amounts of copper and because it is acrylic, there is no silicone to absorb copper. Now if it was copper poisoning, how long would the cephalopod live? It has been 24 hours. Once the damage is done, is it really done? Could I potentially go out, buy a new aquarium, and move the octopus to improve his health? That's very stressful and risky in itself.