Plastic "egg crate" under sand- Good idea? Bad idea?

[Kilman805]

I'm just setting up my tank. The first shipment of live sand and live rock from Tampa Bay Saltwater is arriving Monday.

I'm considering lining the bottom of the tank with plastic egg crate to help protect against any falling rocks. But does it interfere with fish and inverts that like to burrow and filter into the sand? I have 25 lb of sand coming and it's a Fluval Flex 32.5 gallon tank, which I think will be enough for a ~1.25" thick sand bed. The egg crate I have is pretty thin, so I might have about an inch of sand above the top of it if I use it.

Good idea or bad idea?

 

[jgabbsxx]

I'm just setting up my tank. The first shipment of live sand and live rock from Tampa Bay Saltwater is arriving Monday.

I'm considering lining the bottom of the tank with plastic egg crate to help protect against any falling rocks. But does it interfere with fish and inverts that like to burrow and filter into the sand? I have 25 lb of sand coming and it's a Fluval Flex 32.5 gallon tank, which I think will be enough for a ~1.25" thick sand bed. The egg crate I have is pretty thin, so I might have about an inch of sand above the top of it if I use it.

Good idea or bad idea?

My tank has about a 2.5-inch-deep sand bed. I have 2 Wrasse in my tank that burrow under the sand. I would think that an egg crate below the sand may bring up potential to injury when they go under?? I could be wrong, but I wouldn't add that under the sand bed.

Depends on what fish you are keeping in the tank, but an inch of sand bed is a little small in my opinion.

 

[stewy14]

dont, the sanded is gonna have many things tunneling through, it will also mess up the position of the rock if the sandbed is not deep enough, listen to others too, I may be wrong, may be right!

 

[PharmrJohn]

Man.....I WISH I could remember why my knee-jerk response is no! But I can't. I looked into this about 15 years ago and got my answer when I was setting up my 75g. Thanks!!!! Now it's gonna bug me!!!!

 

[Darstar301]

I was told not to do this unless you are placing rocks on a bare bottom tank. LFS said that it starts to have bad pocket under the rock with the deep sand. I guess I did not want issues and have to dig out the egg crate.

 

[dakoop]

I would not

 

[exnisstech]

Egg crate will just trap stuff and as mentioned could cause problems with sand dwelling critter. If your really concerned put a piece of starboard down first. Personally I've never worried about having the rock on the glass.

 

[56longroof]

Eggcrate plenums are only effective when running a deep sand bed. With a sandbed that shallow I would think it could become a nutrient sink and cause more trouble.

 

[Kilman805]

Wow, thanks everyone. I think this is one of the very few threads I've seen on Reef2Reef where there's a unanimous consensus! Conclusion: egg crate under sand is a bad idea.

May I get your thoughts on the amount of sand that I'm getting? I measured more carefully and the bottom area of the tank is about 383 square inches. So, I think the 25 lb of live sand I'm getting should fit it to 1.5 inches, not 1.25 inches. Or should I see if I can add a bit more sand and get to ~2 inches?

I should mention, the tank is too small for wrasse, but I would like to have a watchman goby.

 

[exnisstech]

Here's a Calculator

 

[Kilman805]

Here's a Calculator

Yes, thanks, that's the one I'm using with "crushed coral" as the selection. I think the Tampa Bay sand tends to be pretty coarse and may not pack as densely as fine sand.

 

[PotatoPig]

From your post I’m not sure if you’re doing this or not - but if you have rocks and sand you should always put the rocks in first so they sit directly on the glass. These rocks are soft so shouldn’t cause issues with the glass.

If you put the rocks on the sand then burrowing fish or critters will undermine the rocks over time and cause them to shift, possibly in damaging ways.

 

[kc4mnp]

All of my tanks have been set up with 1/2 inch thick white egg crate from construction supply house wrapped with vinyl window screen and the area that it meets and overlaps sewed together with a needle and upholstery thread ! That way you get the dead air space for the microscopic critters and no injuries to burrowing animals or fishes , etc. my first tank was a 55 gallon with this setup on top of undergravel filters with a power head on top of the stack that came out of the filter in each corner for high flow from the top down through the gravel then the egg crate and screen and then the underground filter then over to the corners up through the powerheads to do it all again... When i took it all down 20 years later the screen was still good and the system still worked good ! Only differance on my new tank I set up 6 months ago was i couldn't find a set of undergound filters with the corner stack type clear pipes so that part didn't get setup , just used the egg crate material and vinyl screen this time and seems to be workin ok so far ! Sorry for the Long Text...Have a Good Day and Good Luck!

 

[56longroof]

@kc4mnp How deep is your sandbed?

 

[Dan_P]

I'm just setting up my tank. The first shipment of live sand and live rock from Tampa Bay Saltwater is arriving Monday.

I'm considering lining the bottom of the tank with plastic egg crate to help protect against any falling rocks. But does it interfere with fish and inverts that like to burrow and filter into the sand? I have 25 lb of sand coming and it's a Fluval Flex 32.5 gallon tank, which I think will be enough for a ~1.25" thick sand bed. The egg crate I have is pretty thin, so I might have about an inch of sand above the top of it if I use it.

Good idea or bad idea?

Ever hear of rock crashing through an aquarium bottom?

 

[GARRIGA]

Egg crate is pretty thin and can also use undergravel plates. Doubt sand burrowers would care since they'd find the glass were the crate not there. Fish aren't inept. Perhaps make the sand deeper on the edges and back so they have a deeper footing to burrow into.

 

[Cichlid Dad]

I run egg crate on the bottom of my tank, put rock in then crushed coral topped of with TBS live sand. I don't have wrasse that bed in the sand and I have no issues. I can't comment on using this setup with fine sand though. Maybe that would be different

 

[elessar333]

All of my tanks have been set up with 1/2 inch thick white egg crate from construction supply house wrapped with vinyl window screen and the area that it meets and overlaps sewed together with a needle and upholstery thread ! That way you get the dead air space for the microscopic critters and no injuries to burrowing animals or fishes , etc. my first tank was a 55 gallon with this setup on top of undergravel filters with a power head on top of the stack that came out of the filter in each corner for high flow from the top down through the gravel then the egg crate and screen and then the underground filter then over to the corners up through the powerheads to do it all again... When i took it all down 20 years later the screen was still good and the system still worked good ! Only differance on my new tank I set up 6 months ago was i couldn't find a set of undergound filters with the corner stack type clear pipes so that part didn't get setup , just used the egg crate material and vinyl screen this time and seems to be workin ok so far ! Sorry for the Long Text...Have a Good Day and Good Luck!

I agree, except for using this in conjunction with underground filters (which draw water through this dead space you created). The point to a dead space created by eggcrate/ luorescent light diffusers, wrapped by plastic screening, is to keep an ANAEROBIC space, with little/no flow, so that the correct bacteria can grow, which take nitrates and convert them back to N2 gas, eliminating the nitrogen from the system. I still use this in all my tanks big enough to accommodate this setup.

 

[Johnd651]

i asked the same thing a week ago. I remember this was a thing 14 years ago with my last set of SW tanks. Recently I ended up just putting the rock on the glass, epoxy puttying the rockwork, and then sand around it, to avoid falling rock.

Not sure if its true or not, but maybe reef safe epoxy wasnt a thing back then? I remember using egg crate was for falling rock, but i also remember mixing sand with cyanoacrylate a long time ago.

 

[RWReefer]

I want to offer an alternative solution to just no. I was also looking at having sand dwelling livestock but I also wanted to save most of my rock work so the bottom wasn’t covered by a couple inches of sand. Instead I laid out my rock scape and identified all of the points where the rock would be in contact with the bottom. From there I mapped out on egg crate underneath each touch point. The theory being that between the rock work on the sand bed would be all sand, but it would also have the stability underneath the rock while also elevating my scape above the sand depth and preventing the rock from sitting directly on the glass.

I glued 3 layers of egg crate together for each under rock design to give save about an inch of rock from being covered in sand. The goal for me was to have enough egg crate footprint to stabilize the rock without having it visible outside of the rock footprint.

I’ve got little egg crate shelves under each touch point of rock in this scape. No movement from the scape whatsoever. All the caves and routes you see between the rocks are 100% sand underneath. For the larger rocks that might have 2 or 3 touch areas, I created a small shelf for each one so that sand dwellers still have the opportunity to burrow under without compromising the structure.