How do I secure LR to an overflow?

[Anonymous]

Hi all,

I'm installing a pretty monster tank for a customer...it's going to be a 4 foot cube, and it has to be viewable from all sides. This means the overflow will have to be right in the center of the tank (imagine a big square donut). I'd like to cover it up with rockwork, but I've never done this before. How do I secure it to the overflow?

...and if you're a local, it's going in a restaurant/bar in Vacaville called 'Zen', along with a 125 or so reef tank. Lucky me

 

[Anonymous]

Zip ties and underwater epoxy.

 

[Anonymous]

Can you build a frame out of pvc that fits around the central overflow and secure the rock to that? We used a pvc frame in our tank to put the rock on because we wanted a hollow area behind the rockwork for the big fish to hide, and it worked rather well.

 

[Anonymous]

That's a good idea! I'm a bit nervous about zip ties though. They have the tendency to become brittle and crack over time. Any other options? Thanks!

 

[shellshocked]

I attached rock to an overflow by cutting a piece of plexiglas to fit then I used stainless steel screws to screw into the rock from the back of the plexiglas. I even built a shelf in the middle and created a ledge. If you have to make some bends it gets harder but there are directions on the internet on the temp and techniques to heat it and bend it.

 

[monkeyboy]

I attached rock to an overflow by cutting a piece of plexiglas to fit then I used stainless steel screws to screw into the rock from the back of the plexiglas. I even built a shelf in the middle and created a ledge. If you have to make some bends it gets harder but there are directions on the internet on the temp and techniques to heat it and bend it.

Yikes, the stainless steel screws will indeed rust over time, not to mention what they leach into the water. You want to use only inert stuff, like plastics.

I'd say a nice PVC frame around the overflow will give you something to work with. If you don't want to deal w/ zip ties, what about some plastic cable or monofiliment line? I think zip ties would be the easiest way to go, and pretty darn reliable. If each rock is tied to the frame w/ multiple ties, I don't think you have anything to worry about.

Post pictures of this beast when you're done. Is it really 4 feet high?!

 

[Anonymous]

Yup. I already maintain a 4' tall x 4' long by 3' wide tank. What a pain.

 

[monkeyboy]

Hah, just don't drop anything while you're working in it!

 

[Anonymous]

Try to find UV rated zip ties. They'll probably go longer withouth getting brittle. PVC frame seems like a good idea. You could zip tie the rocks to the pvc, then epoxy them together. Once the epoxy cures, cut the zips and remove them.

Another Idea I'm playing with is casting resin. I'm tempted to cast some live rock shapes/textures and build a 'rock overflow" from plastic casting resin.
Some rocklike wall that;s actually plastic and functional. I'll let it cover with coraline and you'll not be able to tell the difference. just have to find the perfect liverock arangement and cover it with mold compound. Then cast some positives and go crazy with a dremmel/router.

B
(if someone mass-produces the idea, I need one for a 20 gal!)

 

[witchdoctor]

I made a rock wall by drilling through the rock with a masonry bit, then "threaded" plexiglass rods through the holes. It was a real pain, you need a long masonry bit to get through the big pieces, though I usually tried to find the shortest distance I could. I made the plexiglass rods by cutting strips off of a sheet of 1/2 inch plexi.

I supplemented some of the contact points with chunks of aquarium epoxy, and anchored some of the ends of the plexi rods together with zip ties and epoxy as well, and covered up the joints with smaller chunks of rock onto the epoxy. You can make a surprisingly stable structure with a couple of well placed rods at different angles.

 

[Anonymous]

Hah, just don't drop anything while you're working in it!

I already have, several times. A long pair of tongs and my gangly arms come in handy.

What I'm really afraid of is if this thing ever has to be moved. I mean, I have no idea how I'm going to get down in there to catch the fish. When it was set up it was possible to crawl inside of it to make a stable rock structure, but there's no way I'm doing that to catch a lionfish.

 

[WannaBeReefer]

Just break out the ultra light fishing rod and have some fun.

 

[mark78]

I made the plexiglass rods by cutting strips off of a sheet of 1/2 inch plexi.

I am guessing you own a lathe or?

 

[liquid]

I second the use of underwater epoxy. Also, you may consider renting a wet mason saw that's used to cut brick. You can cut your rock in half and put the smooth edge right up against the overflow.

Shane

 

[EyesClosed]

what about using thick fishing wire. does that last over the long term?

 

[liquid]

I'd use zipties and maybe fishing line to hold stuff in place until the epoxy sets. I'm not sure I'd trust them long term (+2-3 yrs).

Shane

 

[Anonymous]

Yes some 50lb test would work great. 50-100 lb test would last a very long time. By the time it breaks the putty and coraline will have made a more natural bond.

 

[ricky1414]

Hah, just don't drop anything while you're working in it!

I already have, several times. A long pair of tongs and my gangly arms come in handy.

Yeah, but some of us aren't 6'9". My cousin is literally 6'5" and he's got like nearly a foot on me. Holy cheese and rice, I'd be out there making a bazzillion dollars in the NBA. You dont even have to make any freethrows, ahem. :wink:

 

[gabemerrill]

Matt,

A couple of thoughts on this one. I would't use anything thats flexible and going to break down like zipties or fishing line, especially in a resturant show tank. I expect acrylic rods, epoxy, and some patience would be the way to go. You could even make acrylic "hooks" and mounting points on the overflow to "hang" the rocks from if you are feeling adventurous.

HTH - Gabe

 

[dizzy]

Matt,
Here is what I would use to secure the rock. It is nylon threaded rod and very strong. Pictured is 24" pieces of 1/4 20 thread but it is available up to 1" in diameter. You can also get the appropriate nylon nuts and washers. I would make another square donut larger than the overflow to drill and tap into that. I would drill holes in the rock and then drill into the square donut and tap. Run the rods through the rock and screw into the tapped holes in the donut. Then take a nylon nut and secure the rock to the rod.. Use nylon washers if needed. The nylon nut can be hidden with a small amount of expoxy and small live rock or shells. I have used this method to secure live rock and I can hide it where you can't see anything. Be sure to start at the bottom and stack each rock on another one to help hold the weight. I'd say under water this stuff would last two or three lifetimes. I agree that it is a good idea to use a masonary saw to saw the rocks flat, but it is not totally necessary. Hope this helps.
Mitch
PS
It is available from MSC shown in picture. It is listed under rod---threaded----nylon. MSC does credit card sales. Just tell them dizzy sent you. :wink: