Egg Crates

[bladeruner143]

Ive read about people using these "egg crates" at the bottom of their tanks so that they can place their LR on top of them with having to worry about burrowing fish knocking them over. Can burrowing fish still burrow in the sand and how deep should the sand bed be if using a setup like this?

[Riverserver]

I would put at least 2" of sand on top of it.

[Star_Rider]

I placed the rock..make sure it's stable then add the sand. this way no sand shift will cause the rock to shift.

I'm not a big fan of egg crate especially in Marine tanks or any tank with burrowing critters..the egg crate doesn't let them burrow to the bottom and it can be left uncovered and unsightly.

[Grins]

I chose not to use eggcrate at the bottom because I only keep a 2-4" sandbed and have a boby. I did make sure the rock was secure on the bottom glass though. If you go the egg crate on the bottom route I'd probably want a deeper sand bed.

[fsn77]

In our 90g reef, I didn't put eggcrate (aka light diffuser) under the sand / rock, as the rock sits mostly on the bottom glass. I've been leary about putting anything larger than a small burrowing goby in there, simply because I'm unsure how stable the rock work would be if a larger burrower was in there and dug multiple holes in the sand at the base of certain rocks. However, I don't think putting eggcrate down first would make me feel any better about it. The only way I'd feel comfortable with a larger burrowing critter in there would be if I cut / shaped the bottom edge of all the rocks so the literally sit flat on the glass (which is easy enough for me to do if I would have thought of it, only time consuming). To me, eggcrate is not so much about adding stability to the rockwork, but raising the rock up that little bit so entire rocks aren't completely buried in the sand.

I'm setting up a 40g reef where I will be putting eggcrate under the rock. It'll have 4" - 5" of sand on top of it. I'm only using the eggcrate to raise up the rock that 1/2", and possibly to distribute some of the weight of the rock more evenly across the bottom glass.

[bladeruner143]

If I dont want to use the egg crate method, is there any other way for me to provide some more stability to my rock structure or is it basically up to the Fish Gods?

[fsn77]

Some people use a stick epoxy to attach LR together:
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=3961&N=2004+113708

I've seen where people have decided how they want their LR to look (stacked it dry outside the tank), then drilled holes in the LR and used stiff plastic rods to hold the pieces together, epoxying the rods / LR in place.

Or, others have built a supporting structure out of PVC pipe, including having some of the PVC coming up through some of the pieces of LR (again, requires drilling the LR).
See about 1/2 way down the page in this post:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=665314&perpage=25&pagenumber=29

[bladeruner143]

Wow, that PVC pipe thing looks pretty good. Do you have your LR secured in some way FSN?

[Star_Rider]

I just set up the rock as a stable base on the glass..the sand is not goig to get under it an neither are the fish.
for rock on top you may want to secure it if it doesn't sit flat.(marine epoxy sticks work good for that.)

[fsn77]

Wow, that PVC pipe thing looks pretty good. Do you have your LR secured in some way FSN?


No, I didn't secure the LR in our 90g at all... Many years of stacking rock in African cichlid tanks made me think I'd be ok. Then, I read how strong certain critters are -- urchins, for example -- and decided I wouldn't be ok having certain critters in our tank (I'm even leary about having a full size sea star). We had a 3" - 4" sand sifting, burrow digging goby in our tank for ~8 months with no problems. I'd be concerned if we had a larger burrowing goby like a 6" goby our friend had, as that fish was capable of completely rearranging his deep sand bed in only a day, which I would definitely have concerns about simply relying on my stacking skills to keep our LR in place. I've considered something simple like drilling small holes and safety tieing multiple pieces together to provide more stability, but I find myself rearranging LR in our tank every couple of months as corals grow or new ones are added. If all the LR was locked in place, that would kind of limit my compulsion to change things up every so often. Although, I must admit that a more elaborate PVC rock rack would be awesome if I had enough imagination and patience to make it work.

I've considered securing the LR in the 40g we're in the process of setting up, but the rockwork will be no more than 12" tall, meaning I wouldn't do anything more than small holes and safety ties, if I even do that. Again, I see myself wanting to be able to rearrange things as needed, so I don't think I'll even do that.

We're quite ok without having an urchin or a sea star, both of which are critters that require some specialized care to be kept successfully over the long term.

[WeeNe858]

its quite pointless to line the bottom with egg crate. the glass base is re enforced for the weight of heavy objects and egg crate actually makes it harder to stack rocks.

[bladeruner143]

Really WeeNe? What about if the rocks fall or something? Can the glass still withstand that?

[WeeNe858]

thats where you hope your rock work skills are not inferior >.<

i really just give it a good shake to see if its stable

but with that said iv dropped a few 5 lbs rocks onto the base of a 200 gallon UNDERWATER without a problem and hope there will be none

[bladeruner143]

Well, Im hoping my aquascaping skills are up to par. None of the rocks in my 37G FOWLR tank have fallen thus far, even though my fish dig out the substrate from under it!

[Grins]

I wouldn't call it pointless. It does help with shifting that some have. But as I said, I chose to forgo it.

[bladeruner143]

Do you guys have DSB? I was thinking that if you have a DSB it might help support the LR and keep it from falling? Is this true?

[Grins]

No, mine is average.

[sharkmatt]

If the rock is stood on the base of the tank, the sand in a dsb could help to stabilise the base of the rock. However if you stand the rock on top of the dsb then burrowing fish are more likely to burrow under the rock and get crushed. Depends how you set it up.

Shark.