Tank replacement!

[TMoct]

I have a 75-gallon bow-front tank (described here), and happened to notice that the glass lid was sagging in the middle. Upon further inspection, I discovered that the "rib" that spans front to back along the center had cracked, and a gap had opened up:

I asked some knowledgeable folks about this, and I got a lot of alarmed reactions -- apparently this rib doesn't just provide support for the left and right glass lid pieces, but actually provides tension to the middle of the bowed glass tank front! So the fact that this ~8mm gap had opened up is a bad sign for my tank. At the very least, the top of my tank was bowing out by 8mm, which wasn't too comforting.

So I ordered a new tank. In the meantime, I rigged up a bar clamp across the center of the old tank to stabilize the head pressure and prevent catastrophe, and cut a piece of plexiglass to serve as a temporary lid, which could slide sideways under the clamp:

Fast forward a couple of weeks for my new 75gal (rectangular) tank to arrive from dfwaquarium.com, and I was faced with removing an old aquarium, replacing it with a new one (in the same spot), with two live occupants -- an octopus and an urchin...

First task, paint the back of the new aquarium:

The paint worked great! I used the whole can over 3 coats. Here's what it looked like while one coat was drying:

Meanwhile, preparing a bunch of bins for the water, rocks, and sand:

My neighbor came by, but just sat around and didn't help at all:

Lots of clean buckets and extra salt water ready:

 

[TMoct]

New stand (boxed up):

Time to start moving the refugium rocks (and water) into the bins:

Urchin's temporary hotel:

Pumping out the water with a small submersible pump:

After getting the water level down to a few inches and removing most of the rocks, it was time to move the octopus. My intention was to lift out the last rock and encourage him to move to a pitcher that I had set up. But when I lifted out the rock, he didn't let go! So I ended up just gently putting the rock (with octo clinging on) into the bucket which was ready. I covered it with a mesh laundry bag to allow airflow:

The empty tank, ready for removal:

... and all the rocks, water, and sand. You can see the submersible pump in the left tank -- I zip-tied the other end of the hose to a big clamp (like an industrial-sized clothespin), which I could clip onto the side of the bins, and it worked great:

 

[TMoct]

Moving the new stand into place:

Filling up the refugium:

Scooping all the sand and placing all the rocks...

All filled up (but very cloudy).

 

[TMoct]

After a *long* day of swapping tanks, I put octopus into his new home. I had checked in on him periodically throughout the day, and he looked fine, so I just tried to leave him alone. However, when I went to put him back in, he was very pale and lifeless looking. He really looked like he was on death's door. In retrospect, he was probably oxygen deprived. So when I went to dump him back in, I had to actually help him out of the bucket. As soon as he hit the water, he seemed to perk up, and he swam (moderately actively) to the corner. I crossed my fingers...

Interestingly, when I checked on him a couple of hours later, he had situated himself in the upper corner of the tank, directly in the stream of the water inlet. Maybe this is too speculative, but I think he knew that that was the source of the oxygenated water.

Anyway, by the next morning he was back to his normal healthy-looking self. Still a little shy because of the change of scenery, but healthy looking.

Here's the new tank after the water cleared up:

And here's the happy new tenant:

 

[tonmo]

wow, thanks for sharing! New tenant seems to approve - looking great!

 

[Harbor WildWatch]

Very nice! That’s a ton of work but well worth it for peace of mind for your home and animal care. Octopus are resilient, I’m sure he’s glad for the new tank too.