Simple DIY rock wall and cave for 5 gallon hex

[Kuhlifan]

I wanted to redo my old five gallon hex to make it into something a little more natural and viewable. You can see the old fruity pebble substrate I had if you look at my avatar. Yeah, not pleasant. This tank was also my first attempt at a planted tank. The Wisteria grew well in it, too well, and ended up being a mass of floating plant at the top of the water. So I ended up with a crazy graveled tank with a wad of plants the fish couldn't get through to find their food and a large decoration in the center that my fish always hid behind.

So now I start afresh.

My materials are several packages of smooth river rocks. Most pet stores sell them. I bought three packages of large rocks at PetSmart for $3 each, and found a good-sized bag of medium/small ones (called accent rocks) at a Dollar Tree for a buck. I used GE Silicone 1 to put it all together. Here are some pictures of the beginning build.

 

[rsanz]

DIY is great fun. Looks neat! Keep us updated.

 

[Kuhlifan]

I started by placing three rocks in the aquarium for a foundation, and then filled in around it with sand. Leave the tops of the foundation rocks exposed so you can put silicone on them and place large rocks on top. Be sure and sort of mound the sand around it though, so it will support those larger rocks which, for a few minutes, will basically be balancing on the smaller foundation rocks. You could always start off by simply putting the larger rocks on the floor for your foundation, but I wanted to save mine for use above the pool filter sand substrate.

 

[Kuhlifan]

Here's the plan: I want to create a rock wall of sorts with a cave at the bottom. When finished, it looks lock a rock slide, which his a cool effect. I built an airstone into the cave, so when it's cured and running, I'll have bubbles coming out through all of the cracks and crevices, which is making me antsy to see this thing up and running.

Here's some things to consider. These rocks are smooth, so you can't rely on the silicone to hold things together that wouldn't otherwise want to be held together. This is the challenge. It took me about two hours to complete, with around an hour time in the middle to allow a difficult connection to dry some. Pick rocks that, when sat where you want them, will sit there on their own without the silicone. Then you can use the silicone to make sure they stay put. It takes patience, but makes for a better finished product.

I started with the foundation stones, then siliconed a rock on top of each. I then laid rocks on the sand between these, which then had rocks siliconed on top of them, linking it all together. After a few layers, I placed my air stone in what would be the interior of the cave.

 

[Kuhlifan]

As you can see from the previous post, I ran into my first challenge when I began to cover my cave. None of the rocks I had were big enough to stretch the span, so I had to place one in the middle of the cave opening to act as a pillar. I have a really poor view of it from the front. Without the water, the acrylic tank is cloudy, so the flash really messed it up, but you can get an idea of how I did it. This central pillar doesn't have a foundation stone, bit should be touching the bottom of the tank, so it will be sturdy. I had to silicone one stone to it, and then wait an hour for it to dry enough to put the next side on.

Then, I began to add the rest of the cave roof/ceiling. After that was finished, I could continue to build up the rest of the back wall of the slope.

 

[Kuhlifan]

From there, it was careful work building up vertically. I used scotch tape to hold the air line in place and added more strips, removing the lower ones, as I made my way up the tank. The silicone is kind of tricky to use. I used a regular caulking gun and a full tupe, which is far cheaper than buying a small squeeze tube (The large tube is more than twice the size and less than half the cost). The problem, however, is a harder flow to control. When you want it, it doesn't come out fast enough. When you lay it down to place your rock, a wad of it comes out while you're not looking. You can alleviate this by disengaging the gun's plunger every time get ready to place a new rock, which alleviates pressure to the tube and keeps more from being squeezed out all over your workspace.


Also, unbend a paper clip, leaving only a small hook on one end. This works great for digging out big globs of excess silicone from between your rocks. It's also helpful for smearing some of that waste silicone into areas where you need some more.


When you find that too much silicone has squeezed out, try throwing some of your sand substrate on it, so it looks more like sediment built up between the rocks than globs of clear chemials.

Here's how it looks from above now that it's completed. When it's cured, I'll add some water and get a shot from the front that will hopefully be more clear. Then I can go into detail about more of the build.

 

[Arturo]

looks good. keep us posted.

 

[rsanz]

Awesome! Now put some anubias nana 'petite' into those crevices!

Or...you know...do what you want to do with it since it's your tank.

 

[serissime]

looks really cool!

 

[sapphire384]

that does look really awesome!!!

good work man!