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First ever post, just got octopus.


Blue Ring
Aug 27, 2007
bizandheath;102820 said:
Hi, my name is Heath and I just got my girlfriend (her name is Biz) an octopus for her birthday. There are a couple of knowledgable shop owners in my town and they were able to set me up with a suitable tank (sealable) that was already cycled and they gave me all of the live rock and sand and the water that was already in it. I had everything set up for ten days or so and tested the water several times before ordering the animal. I put some snails and a ring-tailed shrimp in the aquarium about seven days before the octopus arrived just in case it was hungry right away. We were able to get a bimac and she arrived on Tuesday (10/02/07). We had several name ideas, but we finally settled on "Detective Hachi" (Hachi is the Japanese word for eight).

These were the levels when we put the octopus in to the tank.

pH 8.4
Ammonia 0
Nitrate 5 mg/L
Nitrite 0 mg/L
SG (salinity) 1.021
Temp. 76.1 F

From all of the material I've read, this should be a perfectly comfortable environment for Detective Hachi. It didn't eat anything for four days, so I finally went and bought eight hermit crabs and it ate two of them right away, so it seems like Hachi is now adjusting well. The first two days it mostly hid, but on the third night, it was fairly active and explored the tank for several hours.

Here are some of my questions / concerns that maybe the more experienced octo owners out there may be able to help me with:

She (at least I think it's a she) is a bimac. How can I be sure about identifying the sex?

When I got her, each tentacle was about 10 inches long. Any guesses on how old she might be?

My ammonia went up slightly (from 0 to 0.25) but nothing has died in the tank and I haven't added anything foreign besides the octopus and hermit crabs. What might be the cause? What might be the solution?

According to her size (10 inches) how much / how often should she eat? Or is it OK to just leave the aquarium stocked with crabs and let her eat at will?

Well, I look forward to hearing from some of you soon.
Try to keep the salinity at 1.024-1.026 like a reef tank. :welcome: