Live rock on eggcrate, sand or on bottom?
 

I will be setting up a new tank downstairs, and resetting my current one upstairs. I have seen several different ways that people have set up their live rock, and need to decide how to do mine.

Some are setting it on eggcrate on the bottom glass. What's the reasoning behind this? Is it just to keep it from sliding around on the bottom and not scratching the glass or acrylic? My concern would be that detritus would get trapped there and collect nitrate and phosphates.

And some have just set the live rock on some sand, and some right on the bottom.

My current tank has about 3 inches of coarse sand (sort of like crushed coral and rubble). I have trouble keeping my nitrates low in this tank now, and I think it is because the of the sand. I vacuum what I can, and a lot of crap comes out of it. But much of the sand is under the live rock and at the back where I can't get at it, so I am sure it must be very full of detritus.

So with my new tank and with resetting my old one, I would like to use the same sand, but a lot less of it, just enough to cover the bottom. I would prefer to just set the live rock on the tank bottom, and work the sand around it.

Any comments and opinions about this?

I put eggcrate down first and then the LR. You could just use pieces of eggcrate under the rocks. I used eggcrate because I think it spreads out the weight of the LR. Also, if you have burrowing fish, the LR won't shift and or scratch the glass. Not that that matters IMO.

eggcrate

Also if a larger piece of Lr were to fall and displace the sand, then the eggcrate will prevent the glass bottom from breaking.

+2 eggcrate

+1 for the same reasons...

Although, I'm considering placing a piece of black acrylic on the bottom of my next build with no sand...

Sounds like eggcrate is the winner. Thanks everyone for your help.

depending on your substrate your power heads/ fish may move your sandaroundand youll see the egg crate i may put acrilic down personally should give enough protection from falling rocks especially with sand to cushion it

if you do go eggcrate leave it 2" away from the edges all around that ways you can still scrape the glass to the bottom with a blade and if you have any sand sifters it wont show eggcrate right up against your glass;P


not a fan of just eggcrate under rocks as if your like me i change my scape quite a bit :)

All good points and advice. Thanks again. guys.

And I guess detritus collecting in the eggcrate is a non-issue?

With what I siphon out of my tank every week, there's no way I'd ever have a sandbed again, nor would I use eggcrate. Both trap detritus and ultimately cause problems. Here's what I siphoned out of my 10g at the end of curing LR....

10g Water Change

^ I can vouche for what she's saying too! Her tanks are very, very, very clean I have seen them in person lol.

If you have large rocks piled up that you are concerned with falling just drill holes in them and secure with acrylic rods. No chance of the rocks falling or even moving for that matter. You can do some pretty fancy rock work this way as well.

I've used large diameter ABS pipe cut into various sized sections to support some of my LR. Holes in the sides will allow some movement & help mitigate stagnation in the sand bed. If I were to re scape, I would do similar, but instead of rounds with holes, I'd open the circles up into half or 3/4 sections. I'd also silicone them to the bottom, since keeping them in place was a pain while trying to place the rock on them. I didn't know ABS has a tendency to float. Not an issue in your case since you'll be working with a dry tank.

Something like this, but clean up the edges of course:

https://tsl4pa.blu.livefilestore.com...733.jpg?psid=1

Not sure I'm a fan of the eggrate scenario, since the latticework would seem to have the tendency to restrict flow & sand movement within the individual squares?

also if you are using dry rock for you aquascape, I saw a video on youtube of someone using a hack saw to cut flat spots onto the rocks where they would sit on the glass, I think that makes things a bit more stable

I use the bottom halves of oyster shells as a barrier between the rock and the glass. That way if a sand sifting critter uncovers them they still look natural

I laid egg crate on mine. Did it so I knew my rock would really slide since I was building tall islands and didnt want to all of a sudden have my islands collapse. But if you do eggcrate make sure you have plenty of sand, cause if you dont it limits you to certain sand creatures. Like pistol shrimps, jawfish, sand sifters going through the sand.

I used eggcrate. Dumbest move I made in setting up my tank. Now it's in there for good, so no option to go bare bottom. The sand is blown all over the place, so it's exposed across the entire front of the tank and looks like ****e. I would not do that again....

What if you had just put it under where the rock is? Would that have been OK?

You guys have got me wondering again now.... Someone mentioned a rock falling and possibly breaking the glass if there is no eggcrate. Is that possible? I would think with the water resistance, the rock wouldn't exactly free fall as if it was in just air. In my current tank, most of the rock is fused together with coralline algae, but what is loose sometimes does get knocked down by an urchin. But with my sand bottom, no harm gets done.

This is why I've used sections of ABS pipe with holes in them. They don't take up the whole bottom like a rack of eggcrate, although you could cut that into sections as well. Other advantages of the ABS is that you can silicone the individual pieces to the bottom so they don't shift, you can cut them different sizes & shapes to accomodate rock shapes, holes & sections allow movement of sand & don't obstruct sand sifters as much. Having the rock elevated above the bottom this way allows more of it to be out of the sandbed & I think aid in filtration. My female Maroon clownfish has blown much of the sand away around her territory partially exposing a couple sections of the ABS, but eventually it gets covered with coralline, so not as much of an eyesore as white eggrate. The eggcrate should get coralline on it with time too though, I would think. When your tank is dry is the perfect time to do some planning & you can make the ABS technique work to your advantage when scaping. It's probably easier to remove individual pieces of ABS as well, rather than trying to get a large piece of eggrate out of there if you change your mind.

Putting it right under the rock isn't going to protect your glass if you were to drop a piece somewhere else later. So why bother? It's also bound to get exposed and looks ugly. Biggest reason in my mind is wrasses though. Mine dive full speed into the sand and move pretty fast under the sand finding a sweet spot. They're clearly hitting glass and then sliding along it. I can easily see them getting beat up doing this on eggcrate.

I used egg crate under my rock and don't find it has caused any problems, but second the opinion to keep it away from the glass - especially in front, or you will see it if the sand shifts. I have a 2 inch sandbed and have a jawfish who seems happy. I don't see the egg crate so it doesn't cause me any concern & when I switched tanks over a few years back when the tank was about 5 years old the sand was still great and there were no pockets of yucky stuff. I definately wouldn't cure rock with sand or eggcrate though - when I did that I did it barebottom and did a ton of water changes.

So, your recommendation would be just to set it directly on the glass? That was actually my initial plan, and have a thin sand bed around it (maybe 1 inch deep), which would still protect my tank bottom from a falling rock.

BB now and rock direct on the glass but when I had the DSB made little boxes out and eggcrate and zip-ties to support the rock. This was so I wasn't burying the rock under 4+ inches of sand and by having the platforms rather than continuous support still allowed critters to burrow around the LR.

Has anyone actually heard of rock falling and breaking a tank bottom? I wouldn't think it likely, they fall in slow motion in the water... but you never know. I think a piece of 1/8" Plexiglas would be better than egg crate if you're worried about your glass.

I would still raise the back of your rock up on stilts to get flow across the bottom of your rock. Any rock surface buried in sand is wasted. Leave the door open to go bare bottom if you find your nutrient levels aren't where you want them.

I highly doubt it's possible in reefing. You either have manageable sized rocks in a smaller thinner-bottomed tank or you have massive boulders with a 19mm bottom or thicker. I can't see it happening and the risk at the very worst can't be great.

I did drop a rock and blow the bottom of my frontosa tank out back in the day though. They were juvies and the tank was only a 45 gallon. Difference being I was using heavy rundle rock slabs. Our rock is WAY lighter you're right.

So yeah rock right on glass. I'd consider pegs of some sort if they're short to elevate the rock but I'd never do it with eggcrate.

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So what happens if one grain of sand gets between the egg crate or oyster shell and glass?

I'm sorry, but that fringes on ridiculous. The rock is not going to focus it's mass on one grain of sand and break glass. ""IF"" it focused that much mass on a single grain of sand, the sand will crush. Or it will puncture into the bottom of the rock. Or get squeezed out sideways.

I have always laid my rock on bare glass. I've dropped 5 pound pieces of rock in the tank (with water) and had it hit glass. The eggcrate is not dispersing weight to save glass. Just not happening. My holding tank has 3/8" glass on the bottom, I filled it for months with 140 pounds of rock that I flipped and flopped around while rummaging for certain pieces.

Here's an example. I needed to remove a cross brace from a tank. Figured a hammer was the quickest way. It was utterly amazing the force I had to hit it with to actually break it. A rock tumbling 8 inches in water to rest on your glass is not going to break anything but corals.

I have seen once, and only once, where a rock, about 40 pounds, fell 2' in huge tank and actually broke the bottom.

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Sorry, I didn't mean to sound harsh, but that is one scenario that can't happen. Both the rock and the sand are softer than the glass, and either will give before the glass.

Oh SNAP! :lol:

Reminds me last year when I was installing a new light fixture for a bathroom. It was on a full wall mirror, and got the old one off, no problem, and the new one fitted on nicely. But then I was tightening (just one more little bit of a turn) up the rear back plate that was against the mirror through a drilled hole to the wall,...I heard this horrible snap, and a big crack ran out from under the back plate.

Had to pull off the whole mirror which was glued to the wall, piece by piece, and using a hammer to break more pieces to get it off.

That was not a good day....

How did sand get back there?

lol. This example more closely demonstrates flexion across an uneven stand. Which would break the glass, possibly.

If you wanted to put something down, the starboard product is often used. (cutting board material).

How about a light diffuser panel like this. It might actually look cool. Darn, why didn't I think of this a month and a half ago.

Hmmm, yeah, I like that. At the least it might keep my live rock from slipping around on the glass. Wonder if HD carries it. I am sure I have seen it somewhere. Thanks for the suggestion.

I'm still not sure how live rock is going to slip around on the glass...it's rock, it's just going to sit there. I ran BB tanks for years, and never had rock slipping around...