Constructing rock structure and seeding dry rock

[Stu]

For my 30 gal that I will be setting up in a few months, I want to build a rock structure that resembles a bonsai tree, with one main tower and rock branches coming off this main "trunk." I got the idea from a pretty remarkable tank thread on RC:

 

http://www.reefcentral.com/forums/showthre...postid=11540863

 

That guy used a bunch of acrylic rods, drilled holes, and zip tied and epoxied rocks together for support.

 

I would like to do the same thing, but I will be using dry rock--so no need to worry about live rock drying out while I make the structure. I am thinking it would be easier and more structurally sound if I used cement to attach the bigger pieces. Does anyone know if this would be reef safe, and which cement to use if it is?

 

Also, how long does it take to seed dry rock? I have a few months before I set up the tank, so I am thinking I could make the structure, then seed it in a trashcan. Any thoughts on how long it takes for dry rock to become biologically effective LR?

 

 

-Stu

[dbartco]

cement will affect ph and will need to sit in water for a while before you can put it in the tank. You may be better with just epoxy, rods, and ties.

 

seeding rock depends on how much you seed with, circullation, and how much diversity on that. A little bit of low lighting won't hurt either. A month sounds sufficient.

[Stu]

cement will affect ph and will need to sit in water for a while before you can put it in the tank. You may be better with just epoxy, rods, and ties.

 

seeding rock depends on how much you seed with, circullation, and how much diversity on that. A little bit of low lighting won't hurt either. A month sounds sufficient.

 

 

Do you know how long it will affect ph? Like I said, it will be in the trash can for a couple of months. Will that be long enough? I'm going to have one or 2 big mag drives, so plenty of circulation, a heater, and probably a skimmer. Also, will it swing so much that it will cause die-off with the seeding live rock? I do plan to put some light over it to encourage coralline growth.

[NemesisElite]

today i just started making my rock for my new tank using the skills almon presented at the FF.

 

ill post an update later to see if it was worth my time

[capsfan]

today i just started making my rock for my new tank using the skills almon presented at the FF.

 

ill post an update later to see if it was worth my time

 

I hope it goes well. Good luck!

[Origami]

Stu, use portland cement mixed with aragonite crushed coral or aragonite sand. You should cure newly manufactured "aragocrete" before trying to seed it. Six to eight weeks is typical for curing time of aragocrete rock. It may be shorter in your case because you may not be using much of it. You should change the water out as much as daily, though. Scan the info in this link (it might be helpful): http://www.garf.org/class.html

[Pat_13]

3/4 of my tank is home made reef rock. Made an overflow cover that has several ledges. Let me know how it goes and take pictures.

[blaze98]

I have a ton of extra portland type I/II if you need some, a little goes a long way. I have been using Almon's recipe of 4 parts aragonite and one part portland and it works fine.

[Stu]

Hmm...6 to 8 weeks is a long time. I was hoping it would be more like 2. I may just go with the rods/epoxy route. Anybody else have any opinions on cure time? It would just be the connecting joints of the rocks, and not the actual rocks.

 

Blaze, thanks for the offer. At fragfest, Almon said those frag plugs only need to cure for a day or two if I remember correctly. I guess it's cause they are so small. Do you think that the cement connections would need the full 6-8 weeks?

[Jon Lazar]

Stu,

 

Keep in mind that zip ties, epoxy, and other mechanical attachments will eventually be overgrown with coraline. So long as these items are flush with the rock, they will disappear into the rockscape.

 

But if you have a piece of clear acrylic sticking out from the rockscape, it will become much more visible once it turns purple. People have found this true when constructing acyrlic shelves to make crazy arches. The acrylic is clear at first, but soon gets covered in coraline and detracts from the overall look.

 

The tank you linked to is a great model to use for your inspiration. Good luck!

 

Jon

 

For my 30 gal that I will be setting up in a few months, I want to build a rock structure that resembles a bonsai tree, with one main tower and rock branches coming off this main "trunk." I got the idea from a pretty remarkable tank thread on RC:

 

http://www.reefcentral.com/forums/showthre...postid=11540863

 

That guy used a bunch of acrylic rods, drilled holes, and zip tied and epoxied rocks together for support.

 

I would like to do the same thing, but I will be using dry rock--so no need to worry about live rock drying out while I make the structure. I am thinking it would be easier and more structurally sound if I used cement to attach the bigger pieces. Does anyone know if this would be reef safe, and which cement to use if it is?

 

Also, how long does it take to seed dry rock? I have a few months before I set up the tank, so I am thinking I could make the structure, then seed it in a trashcan. Any thoughts on how long it takes for dry rock to become biologically effective LR?

 

 

-Stu

[droyal1110]

Like Nemesiselite said (my brother) we started making the rock work for his 30 gallon yesterday, believe me its a learning curve, its simple yet tedious.

 

To make the bonsai tree I would recommend starting out by making a foundation for the rocks, make it nice and wide, and while its wet stick a piece of pvc pipe in there. Now while experimenting yesterday I found a couple of ways that could work for attaching rock work. You could get a 3/4" PVC pipe, and get a straight PVC fitting that fits over the 3/4" pipe. Make your foundation, while wet stick the fitting into the cement (so its pretty flush with the rock) and let dry. Now make your flat piece of your bonsai tree, and stick the PVC pipe into the bottom side of it (make sure you have a little bit sticking out so you can attach to the fitting on the other rock) and let dry. The next day, stick them together and you just formed part of your bonsai tree.

 

Now if you were doing a high branch, you could just use a long piece of pvc, let the pieces dry, then the next day coat the pvc with the cement rock combo until you're satisfied how it looks. If you don't understand this I don't blame you, I can draw pictures in MS Paint.

 

If you're going to be starting up a new tank, why not just make your rock, let it dry 48 hours, put it in the tank you're going to cycle, and let it soak and cure while your cycle is going on. The PH isn't going to kill anything since you're cycling your tank without livestock anyways. Or, like you said you're going to be using a trash bin for a few months, this will be plenty of time to let the rock cure. Just treat the bin like your fish tank, put the rocks you want in there, buy some live rock and throw it in the water (the die off will kick off a cycle), buy pieces with coraline algae on it already and put a good light above the bin, and presto you just started a fish tank in a non-see through tank. Do a water change once a week for the first month to help get the nasty stuff left behind the DIY rock, and just let it marinate. When your ready to transfer it over, make sure you have water ready in your new tank and make sure the rocks are exposed to air as little as possible to help minimize die off.

[Origami]

Hmm...6 to 8 weeks is a long time. I was hoping it would be more like 2. I may just go with the rods/epoxy route. Anybody else have any opinions on cure time? It would just be the connecting joints of the rocks, and not the actual rocks.

 

Blaze, thanks for the offer. At fragfest, Almon said those frag plugs only need to cure for a day or two if I remember correctly. I guess it's cause they are so small. Do you think that the cement connections would need the full 6-8 weeks?

 

Since the "curing" process is one of leaching of chemicals back into the water, the curing time would depend mostly upon how deep/thick the rocks (in this case, the cemented portions) are. The impact to your aquarium would depend upon how fast and how much of these compounds were leached back into the water, and how fast they could be removed. I think that Almon said that most plugs needed to dry a day or two (the longer dry time was for the plugs he made in the baby bottle nipples). In a personal conversation with him, he tended to leave them in water for a week or more. However, since they're small and relatively thin, and because his tanks are relatively large, premature use of a few plugs would probably not have a large impact.

 

The best way to do this is to start soaking the rocks after the cement has set up and "cured" (to hardness). Make sure that you soak them in a lot of water. In the initial days, you may get a gray scum that forms on the top of the water. This is likely the quick stuff that's being leached out. Change the water frequently in those initial days. Monitor pH swings from when you put new water and in the ensuing days. Leaching should cause an shift upward. Once this shifting settles, you should be good-to-go.

 

Six to eight weeks is for aragocrete rocks. Since you'll likely be using far less cement, I suspect that the process will be quicker.

Edited July 1, 2009 by Origami2547

[Stu]

I'm thinking that because a 30g isn't all that big, and it will probably take all of a Saturday afternoon, I'm going to go the zip tie-epoxy-rod route. I also won't have to worry about changing the "cure water" out regularly. The only thing is I would like to fill in the gaps where the rocks connect, and make it look more like one big fluid rock structure, rather than a bunch of rocks stuck together.

 

I saw a few threads on RC where people used "Great Stuff", that expanding foam, to make false back rock walls and structures. While I don't want to make a structure completely out of this foam, I thought it might be a good way to fill in the gaps and maybe add some support as well. I figure I could sprinkle sand/rubble on it while it's still drying to look more natural. Also saw some folks using regular silicone to fill gaps/cover zip ties, etc. Anyone tried this?

[capsfan]

I'm thinking that because a 30g isn't all that big, and it will probably take all of a Saturday afternoon, I'm going to go the zip tie-epoxy-rod route. I also won't have to worry about changing the "cure water" out regularly. The only thing is I would like to fill in the gaps where the rocks connect, and make it look more like one big fluid rock structure, rather than a bunch of rocks stuck together.

 

I saw a few threads on RC where people used "Great Stuff", that expanding foam, to make false back rock walls and structures. While I don't want to make a structure completely out of this foam, I thought it might be a good way to fill in the gaps and maybe add some support as well. I figure I could sprinkle sand/rubble on it while it's still drying to look more natural. Also saw some folks using regular silicone to fill gaps/cover zip ties, etc. Anyone tried this?

 

I would probably go with the foam before I went with silicone just because of drying time. I have seen the rock walls made with the pond foam and they look nice with the rubble covering the foam.

[Origami]

Go with the foam. I've seen this process described on RC: Apply the foam & let it expand. Tear it out after it's dried (cured) to give it an irregular, rough look. Give the foam a coat of epoxy paint (as a protectant and an adhesive), applying (aragonite) sand / gravel to the paint before it dries to give it a natural look.

 

I don't know if the paint step is really necessary. I think the author of the thread that I'm recalling did it to improve the color (to go from that Great Stuff yellow to black) and to protect the foam since he didn't know how it would age in saltwater.

 

Pond foam's already black (I think) and shouldn't have issues in water (I suppose), so it may be the quickest, most simple route for you.

 

Drilling and securing rock with zip ties to a PVC, acrylic, or egg crate frame is done often with good results. If you go this route, you're using a tried and true method. Good luck!

[DaveS]

Drilling and securing rock with zip ties to a PVC, acrylic, or egg crate frame is done often with good results. If you go this route, you're using a tried and true method. Good luck!

 

Any one recommend some really good URLs for this? I may be looking to do this with my live rock and reaquascaping. I've researched the pillar stuff alot but not the more common techniques.

 

Thanks.

[Stu]

Go with the foam. I've seen this process described on RC: Apply the foam & let it expand. Tear it out after it's dried (cured) to give it an irregular, rough look. Give the foam a coat of epoxy paint (as a protectant and an adhesive), applying (aragonite) sand / gravel to the paint before it dries to give it a natural look.

 

I don't know if the paint step is really necessary. I think the author of the thread that I'm recalling did it to improve the color (to go from that Great Stuff yellow to black) and to protect the foam since he didn't know how it would age in saltwater.

 

Pond foam's already black (I think) and shouldn't have issues in water (I suppose), so it may be the quickest, most simple route for you.

 

Drilling and securing rock with zip ties to a PVC, acrylic, or egg crate frame is done often with good results. If you go this route, you're using a tried and true method. Good luck!

 

Thanks for all the useful info. After reading some of the foam builds over on RC, I think I'm going to do the following:

 

1. Use a heavy piece of rock for a solid base

 

2. Use rods as a skeleton, and zip tie "branches" off the main "trunk"

 

3. Fill in the gaps with black pond foam

 

4. Trim the foam with a razor so it looks more natural

 

5. Coat the foam with epoxy and sprinkle sand/rubble while it's still drying

(I want to do this because I would rather not have big sections of black foam in my rockwork while I wait for coralline to grow over it.)

 

6. Seed structure with LR in trash can for a couple of months

 

One more question: What epoxy should I use? I will be brushing a lot on over the foam, so what is the most economical route to take?

[Origami]

One more question: What epoxy should I use? I will be brushing a lot on over the foam, so what is the most economical route to take?

 

Don't know. But I'll bet you can find an epoxy paint that might work over at Home Depot or at Lowe's.