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My 90 gallon Octo Tank (Work in progress)

Cody

O. bimaculoides
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Mar 9, 2011
Messages
67
I'll (hopefully) be uploading pictures as I set up my 90gal tank for which I will keep an octo of an unknown species at this point in time. (Haven't decided / depends on availability) But here's the stand and then the filter that I have made/put together myself! (I didn't make the stand, but I did make the filter is what I'm saying...)

This is the filter, which will be going into a plastic "sump", if that's possible xD
The top is polyfiber, phosphate, and carbon. The second drawer has bioballs.


And this is the stand, which, at the time has some stuff in it, obviously.
 

Cody

O. bimaculoides
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Mar 9, 2011
Messages
67
Alright so I have a question... my tank came with a plumbing kit... 1 & 1/4" drain and 1" return.. I don't know exactly how to plumb the water to and from and how to put the bulkheads onto the tank... (I know you have to use the rubber pieces) But if anyone could help that would be greatly appreciated! Also, not sure what size tubing to use to transport the water........ :/ More pictures coming soon.
 
Joined
Sep 25, 2006
Messages
563
Cody;174982 said:
Alright so I have a question... my tank came with a plumbing kit... 1 & 1/4" drain and 1" return.. I don't know exactly how to plumb the water to and from and how to put the bulkheads onto the tank... (I know you have to use the rubber pieces) But if anyone could help that would be greatly appreciated! Also, not sure what size tubing to use to transport the water........ :/ More pictures coming soon.
The bulkheads will either have male barbed fittings for vinyl hoses, or female pvc slip fittings. The pvc pipe or vinyl tubing should be 1" of 1 1/4" (inside diameter) to match the bulkheads. If you use pvc pipe, use pvc pipe glue. You can also order fittings that convert pvc to barb fittings, so you can run pvc pipe for part of the way, and then vinyl hose for where you need flexibility.
For the bulkheads you need one rubber seal for each bulkhead, and it needs to be sandwiched between the glass on the inside of your tank, and the flat flange on the part of the bulkhead with the threaded tube (shaft) on it. Slide the rubber ring over the threaded shaft, then from the inside of the tank, push the threaded shaft through the hole in the glass. Then put the nut part of the bulkhead onto the end of the threaded shaft that is sticking out of the hole, on the outside of the tank. Tighten the nut down with your hands (and maybe a gentle final nudge with a wrench, but not too tight or the plastic might break).

I use bioballs in a wet/dry filter on my 60 gallon bimac tank. As a rule of thumb, I think you will need to have a volume of bioballs that is equal to about 10% - 15% of your tank volume for a tank fully stocked with fish. That would mean 9 - 13.5 gallons of bioballs for a fully stocked 90 gallon tank. If your octopus, and tankmates constitute a bioload that is less than a full compliment of fish, then you can reduce that accordingly, but I'd say you'll need at least 5 gallons of bio balls. I feed my cold water bimac tank very heavily (lots of filter feeders) and I get by fine on 9 gallons of bio-balls in a 60 gallon tank with a fully grown bimac). It looks to me like one of those drawers can only hold between one and two gallons (231 cubic inches in a gallon), so you might need to rethink your filtration. I also found that if I only had a small crack to let fresh air into my bioball chamber, that I got low PH due to insufficient gas exchange. An opening of about 12 sq in on top has been sufficient. You might need to cut air holes in the top edges of the bioball drawer(s) if you find that your gas exchange is not good enough. Good gas exchange is especially important for an octopus. You'll need a way to spread the water out and sprinkle it evenly over all the bioballs, so that all of their surface area is always wet. I use a flat acrylic tray with lots of holes drilled in the bottom.

Note: I don't use any live rock, so my bio balls need to do all my filtration. If you will be using live rock, you can get away with less than 5 gallons of bioballs (or none at all). If you don't use live rock, you'll need another way to keep nitrate from building up, like a Remote Deep Sand Bed (RDSB), a nitrate filter, or lots of water changes.
 

Cody

O. bimaculoides
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Mar 9, 2011
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Yeah, I have a gallon of bioballs in that little drawer. I was debating today whether I should just get a carbon sock and then bioballs and put them in that plastic basket protector ( the thing with the toys in the second picture) and split it up instead of using the whole filtration method that I made.
 

Cody

O. bimaculoides
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Mar 9, 2011
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I'm going to end up not using the filter trays that I built; and rather than those go with a filter sock and protein skimmer in place of them. More pictures of the tank/overflow when I get home today!
 
Joined
Sep 25, 2006
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563
Filter sock and skimmer (oversized) is a good plan. I'm assuming that you are also planning to have 80 to 150 lbs of live rock.

Is your tank acrylic? If so, the upside is that you can easily drill, tap, cut, and glue (weld) acrylic to it. That is useful when you need to make it escape-proof.
 

Cody

O. bimaculoides
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Mar 9, 2011
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Nope, it's made my Deep Blue Professional...glass...

Full tank and Stand (Obviously)... They apparently couldn't get the UPC code off of the tank, that's why the "label" is partially missing. I didn't go to pick-up the tank the day we were able to get it.


Overflow from Top


Overflow from Underneath (To make sure I did it correctly)


I also have (as you can see) a Deep Blue Professional heater (300 watts) rated for "80 gallons" and a Surpreme return pump rated at 700gph. I also noticed that it's difficult to see the overflow because of the reflection.. the overflow is built-in, in the back left hand corner of the first picture. I tried to wipe out the tank with just a little bit of tap water on a rag (assuming that it's okay) to try and get the dust and little pieces out but it doesn't seem like that did the trick. Going to have to use a vacuum eventually it looks like.
 

DWhatley

Kraken
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Sep 4, 2006
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You have a nut screwed onto the bulkhead from the bottom side right? I can't tell from the photos. As you build out the plumbing, you will want to leak check it with fresh water and that will let you get out some of the last dust before you fill with your salt water. I would also take out your "sump" and put it in the tub and fill it to be sure it does not leak and is sturdy enough to take the water weight (sides as well as bottom). The Coralife skimmer we talked about can be placed either inside or outside so you can use the full interior of the cabinet like you have it with that style skimmer but the slat of the sump wall may require some MacGyvering to have it vertical.
 

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