Floating Rock Design -- Help??

[El Jefe9830]

Hey guys and gals.

Now that the 300 gallon is cycling, and running. I am in the process of designing my Aquascape. I would like to do a floating rock design, and have tons of ideas.

I would love to see/hear about how people have done it, and any sites/links/pics, etc would be greatly appreciated. I have a couple of ideas, but I have one extreme idea, that I thought I would run by you guys. My goal is to keep the sand bed as empty as possible.

So my idea is to drill some 1 1/2 inch holes in the top of the tank, between the openings (My Tank is 1/2" acrylic). The put through the holes PVC piping Stabilizing it on the top of the tank. Then buliding my complete rock formations on the PVC from the top without ever having any touch the floor of the tank at all.

Is this something that is doable? And what would be the advantages/drawbacks of something like this?

thanks for the help.

 

[limitedslip]

I saw plan designs similiar to what you want to do somewhere, I'll see if i can find it again. I remember It was similar to stacking rocks, but just in reverse, Only issue would be the weight over time, Maybe you can hang and create a counter balance for it on the rear of the tank?

 

[rivoth]

You are going to have a lot of water current pushing those rocks around. This will translate into a fair amount of leveraged torque where the PVC pipe is attached to the acrylic at the top. I'm no mechanical engineer but that could be a problem.

The setup would be a whole lot less stressed if you allowed your PVC pipe to attach at both the top and the bottom of the tank. You could still keep all your rocks off the sandbed but the pipe itself would go through. I know that's not quite the look you were hoping for though.

 

[Kep]

rivoth is right, the force from water motion will eventually strain and crack the acrylic. How about instead of a single pipe, you use three pipes arranged 120degrees on a circle pattern, and attached together through the top, but not to the top. Kinda hard to explain, but if you have the pipes pass through the top (with a little bit of clearance for each) and then an acrylic plate above the top that all three are attached to. That would be a much more stable structure and if the stress did break something it would be the acrylic support plate and not the tank itself.

 

[Myrddraal]

Are you going to have some sort of canopy / light hanger? If so, you could possibly hang your rock from it, instead of the tank itself. You might also be able to use carbon fiber rods instead of pvc, they're a smaller diameter.

 

[reign]

I would use acrylic rods they are smaller in diameter and easier to work with since they solid as opposed to pvc..It would be better to attach the rocks to the light canopy or something above the aquarium...Although if You have a tenecor aquarium it probably wont hurt too much to attach it to the tank since they Way over build them to begin with..You also did not say How much rock you are going to attach to supports. THAT is the limiting factor as to how to support it..

 

[rivoth]

After thinking about it some more you want your top attachment point to pivot freely. That way the island can swing around a little bit without adding additional stress to the attachment.

I think the idea of attaching it to something overhead other than directly to your tank is prudent.

 

[El Jefe9830]

Wow, thanks for all the feedback guys. I posted this last night, half thinking it was a bad idea, but you guys are making me believe that it is a possibility.

Few Notes, my tank is a Tenecore. I don't have a canopy built yet, but I plan to do that. However, I will need to be able to remove it on occasion, so making it the support for the rock formation probably isn't going to work. Acrylic rod is something I was thinking about, and attaching it to the floor of the tank is a possibility in a few areas for support.

I probably should have built the rocks prior to filling it, and cycling it, but oh well. The challenges are always there .

I will try to draw up some pics of what I think might work on paint to post up on here.

 

[El Jefe9830]

OK this is a very rough draft of what I have in my head, but see what you guys think.

Also, I am not thinking about attaching the PVC to the tank ceiling, but Actually drilling a hole through the roof of the tank, and then making some sort of a X on the lid. Try to spread the stress out more than just on what part of the tank. I would like it to be sturdy enough that the water movement doesn't affect it. However, I am not positive how to do that, hence my post here.

 

[thosefishguys]

I did something similar in my 125...I used 1/2" pvc, with a 90 degree elbow at the bottom for support. I drilled 3/4" holes in 3 pieces of liverock, and slid the live rock down over the pvc. The 3 pieces of liverock weigh a total of about 10 pounds, so the weight isn't too bad, and the whole structure hangs "freefloating" from the top of the tank. I didn't attach the pcv to any fixed support, as I wanted it to be able to move a little. I have a powerhead aimed almost directly at it, and it only moves about 1/8" from side to side. Let me know if you are interested, and I'll post a picture this weekend.

Jason

 

[Kep]

For it to be sturdy you need to have at least 3 attachment points that are not in a line. Think of how a table/chair/stool work. It will be fairly similar to that. You need at least 3 points for stability.

 

[Kep]

Jefe, any pics of what you decided to build?

 

[El Jefe9830]

Haven't even started yet, to be honest. Working on getting some other things done, but overall the tank is running very nicely. I have been pretty happy with the system.

I haven't built the hood or done the floating rock yet. I will get some pics up as soon as I get something in progress.

Thanks for the interest.