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Water Changes

May 31, 2006
Ok, so my octos are producing a lot of ammonia since I've gotten them. I'm thinking it's just because they are new to the tanks, but it's been a few days and the ammonia is still above the recommended level. They seem to be doing fine, though. I've been doing daily water changes, usually an hour or two after I feed them. Should I be having to do them everyday?
You should be doing the water changes if you have ammonia. Ammonia should really be 0.

But, if your tank is well cycled, you shouldn't be having ammonia.

Could you describe your tanks - how many tanks, how large they are, how many octos per tank (1, I hope), is the water pumped from one source thorugh all the tanks, or does each tank have its filtration system. What sort of filtration are you using? Do you have a protein skiimmer? What's in the tanks -any live rock? When were the tanks set up for these octopuses?


It sounds like the tank wasn't very well cycled. Once you've got octos in there you've got kind of a catch-22: doing water changes makes the cycle go a lot slower, but not doing them kills the octo!

Well, we don't really have a big system or a lot of space, due to regulations at my university. We have 3 octos, each in their own 10-gal tank. They have aquarium supply filters and heaters. There is no direct inflow or outflow for the system other than the water changes I do, since the University won't allow us to hook up non-native species to the drains. We are not currently using the protein skimmer do to the limited set-up. The tanks were set up sometime around May, and the octos got here on the 20th, so they've only been here 6 days.
Two of them are submerged filters, and one is a hang on the back type (the other submerged one broke). My advisor bought them, so I'm not sure where he got them. But they're the kind I think you might use in a home aquarium. I don't have the brand name handy right now.
Unfortunately, you have some problems. The tank hasn't been properly cycled and is too small for a bimac. Octopuses produce a lot of waste and your tank has no way to deal with this waste. You don't have adequate filtration. For right now your one recourse is water changes.

How big are these bimacs? Are they babies with mantles of 1/2-1 inch, or older? And how long will you keep them in these tanks?

I'm thinking of what the best way for you to proceed will be - maybe some of our other experts in tank chemistry will also offer suggestions.

I agree with Nancy that you've dug yourself in a bit of a hole. Ten gallons will not support a bimac, especially with bottom-end filtration.

Here's what I would do: Pick up 3 30-gallon breeder tanks, buy or build stands for them. Get a 75 gallon stock tank from a farm supply store and set it up as a sump. Set up a drain in each tank "LFS-style," that is, drill a hole near the top, and use a PVC elbow inside the bulkhead (octo-proofed, of course). Have each drain into individual 3 gallon buckets of bioballs (or perhaps one larger rubbermaid) and then into the stock tank; and use a decent pump (Mag 9 perhaps) with the output split into the three lines, one for each tank. You're going to want a real nice skimmer in the sump, expect to spend about $600 on it alone.

Go around to different LFS in the area and see if they will let you borrow or buy bioballs out of their filtration system. That will jumpstart the system, and you might be able to move the octos there within a month.

In the meantime: water change, water change, water change.

This system IS going to take up a bit of space and a bit of money, but the bottom line is you've dropped the ball, you already have the creatures, if you want them to survive its up to you to find that space and money. If you're a little creative with a saw and a drill you could build a stand that will stack the tanks vertically above the sump and fit in a large closet or storage room.

I spoke with Amy and now understand the problem a little better.

It was not planned to keep the octos in such a small tank - she had to move out of the main research room due to a new university regulation - species that are not native to the area cannot be kept in room with a drain. The main research room with tanks has a drain.

As a result, Amy had to set up the octos in a tiny area away from the main research area, which is why the tanks are so small. She even has a large protein skimmer and larger tanks are available - but so far she can't bring this all together.

The bimacs she's keeping have a 3", 2" and 2" mantle.

If you can't connect your tanks directly to the drainage system, what do you do with the waste water? If you are dumping it down the drain, isn't that the same as if they were connected? Not that you want to tell the "authorities" who won't let you connect to the rest of the system... Keep doing water changes, get the skimmer connected! And listen to Dan... How small is this closet?
As always, I apologize if I was a bit curt...the ten gallon tanks sets off a bit of a fight-or-flight reaction! :wink:

The regulations seem a bit draconian. Maybe you could sneak the system into your apartment?

Well, the authorities of the Marine Center won't let me connect directly to the drain, and there really isn't another facility on campus where I could put the set up. Right now the water has to be treated with bleach and then neutralized before being dumped down the drain, so unless I can work that into the system (which I doubt), I can't have anything running directly to a drain. However, if I can set up a closed system, that might be a possibility.

I am speaking with my academic advisor, the head of the aquaculture department, today to see what we can get set up for the octos in terms of a better system. She's got a couple of her students who said they could help me as well. Wish us luck! Until then, I'm going to just keep changing the water as best I can.
Don't worry at all about having it connected directly to the drain. A closed system will do just fine as long as there's adequate filtration and water volume!


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