Final check

[DWhatley]

Peps will be fine in the tank either way but I am curious. If they are easily removed, they are thankfully not aptasia. I have an odd little critter that looks like some kind of an egg when it is floating about but will bury in the sand and feed at night with arms spread upward. It is larger than what you are seeing though. Since they are easily removed, take one out and put it in a shallow bowl of tank water and work to get a GOOD photograph.

 

[Joe-Ceph]

I would also suggest that you stir your sand bed frequently (I do mine weekly). Especially while you are removing water from the tank during a water change...

That may not be good idea if you are running a "deep sand bed" (sand deeper than about four inches) to reduce nitrates. Deep sand beds can house anaerobic bacteria that lower nitrates by converting them to nitrogen gas. oxygenated water will kill the anaerobic bacteria, and Ive noticed spikes in my nitrates after my 4-5 inch deep sand bed gets disturbed (by my octopus digging). If you're sand is shallow, or if you are dealing with nitrates some other way, then disturb away, I just wanted to raise the issue.

You can use a "gravel vacuum" (often used in fresh water tanks) to do your water changes. That way almost all of the "dust" you kick up from your sand will be in the water you remove during the water change.

 

[DWhatley]

Hopefully you are not trying a DSB as a new aquarist and with an octo (I will only do a DSB in a separate tank but others have been successful with different combinations. However, it takes at least a year for a DSB to properly cure and should not be disturbed - not something you can count on with an octopus) but if you are attempting that then don't stir, just siphon off the top. If you have set up a minimal bottom substrate (personal preference) or anything under 6", then you need to concentrate on turning it frequently as it will not provide the chemical advantages of a DSB and can house pockets of gas and rotting debris if not frequently turned.