Egg Crate

[cartandpeg]

Hi,
I am going to be adding rocks to my aquarium and I am ging to add egg crate where they will sit,should I place the egg crate under where only the rocks will sit or cover the whole bottom with it,substrate is sand.I have done a bit of reading but no one has actually said just under or all over.

Thank you.

 

[thereverendturtle]

Is this for fresh or saltwater?

 

[cartandpeg]

For freshwater,sorry negleted to mention that.

 

[thereverendturtle]

If there's not going to be any plants then just place a sheet on the entire bottom. If you're going to also have live plants then just under the rocks. Is there a specific reason why you want to add the egg crate?

 

[cartandpeg]

Thanks thereverendturtle,
I suppose adding the egg crate was mainly due to helping spread the weight of the rocks and also a few of the rocks may well not have a flatish surface to sit on the substrate.

Some of the smaller rocks would sit on about 1 inch of sand and any larger ones would be on 2 to 2 half inches of sand.As my tank has a depth of 70cm,I was going to silicone some rocks together to give me some form of height factor in the tank.

So my thought was putting the egg crate down,putting in the rocks, then adding the substrate.

In respect to live plants,there will be some,most of the plants will be attached to rocks/driftwood,but,if I was to have success with stemmed plants growing,I would dare say I would add more stemmed plants at a later date.

Do you think adding egg crate or the likes my be detrimental,I have yet to purchase the rocks,so I could not give a weight factor on how much would sit in one spot.

Thank you.

 

[raptorrex]

Thanks thereverendturtle,
I suppose adding the egg crate was mainly due to helping spread the weight of the rocks and also a few of the rocks may well not have a flatish surface to sit on the substrate.

Some of the smaller rocks would sit on about 1 inch of sand and any larger ones would be on 2 to 2 half inches of sand.As my tank has a depth of 70cm,I was going to silicone some rocks together to give me some form of height factor in the tank.

So my thought was putting the egg crate down,putting in the rocks, then adding the substrate.

In respect to live plants,there will be some,most of the plants will be attached to rocks/driftwood,but,if I was to have success with stemmed plants growing,I would dare say I would add more stemmed plants at a later date.

Do you think adding egg crate or the likes my be detrimental,I have yet to purchase the rocks,so I could not give a weight factor on how much would sit in one spot.

Thank you.

I wouldn't say "detrimental" more "unnecessary".

 

[cartandpeg]

Thanks raptorex,
My main concern would be the assembly of this one rock formation,if the LFS still has this rock (thinking about it again) I would more than likely be able to make the base of the rock formation flat,so would it be okay just to add my substrate and then place the rock on top of that.

I have been doing some reading since this post and there are some who swear by it and other who have loaded their Aquarium up with pounds and pounds of rock and have no problem,just trying to cover my butt,so too speak,the good wife always tells me I go into overkill mode when doing things,maybe the same here.

As far as I know the glass is 8mm thick on the tank,tank is in transit.

Thanks all for comments,just want to get it right the first time.

 

[Aquascaper]

No need IMO.

The pressure of the rock will be spread and absorbed by the sand (unless you're planning a total rock wall). The only reason for it would be if you have any burrowing inhabitants that may excavate under the rock causing it to topple. In that case just put it under where the rock sits.

The reason we use it in marine tanks is:
1) The sand used is not as fine and therefore means small shells, etc. can be pressed onto the bottom glass causing a pressure point.
2) There are a plethora of burrowing things that can and will undermine rock structures causing them to topple.

 

[cartandpeg]

Thank you very much everyone for the advice,
I will just sit the rock on the substrate,your help is much appreciated.

 

[Aquascaper]

If you want to put you mind at rest make sure the sand underneath has no trapped air and is quite compact and be careful when adding water during maintenance that it doesn't wash out

Some people use a thin piece of polystyrene rather than eggcrate (just to give you an alternative).

 

[cartandpeg]

Thank you Aquascaper,
I will see how the rock looks after I have done my bit with it and I may put a piece of polystyrene just under where it sits,or should I do the whole tank botton,the rest of the rocks will be small and they will be more so, for caves and have Anubias and the likes attached to them.
I think I may feel a bit more content that way.Thanks again.

 

[thereverendturtle]

Ok, by the sound of it, you're doing a cichlid tank. If this is the case, where you are going to have fish that dig, place the rocks directly on the glass or a piece of polystyrene, then place the sand. No matter how much you compact the sand, any fish that dig, cichlids, catfish, loaches and others, WILL dig under the rocks. I have about 200#'s of rock sitting on the glass of my African cichlid tank. The glass is about 6mm. I've had this tank with more rock and less rock, but in 20 years I've had no problems with it.

 

[Aquascaper]

A strip big enough for the rocks to sit on is fine, if you cover the whole tank bottom the fish could break it, releasing pellets into the tank which could be ingested.

If you have to cut the polystyrene and don't use a hot wire you can seal broken edges with a hot air gun (possibly a hairdryer) to stop it breaking up.

 

[Hermithall]

How does Raptor know for sure it's unecessary? It can and does happen, and the problem of cracking the glass arises when too much weight is concentrated on a single point of contact, i.e from the sharp corner of rock against the bottom of your tank with all the weight from the rock above bearing down on that point of contact. It puts me in mind of breaking a car window just by the pressure of pushing a tungsten carbide tip against the glass. Most of the time we'd need a physicist to come and assess the actual scientific likelihood of our glass breaking, which probably isn't convenient, so get yourself a bit of egg crate mate if you're at all worried about the weight. For me I know with only 25kg of rock sitting on 10mm glass it probably wasn't necessary, but I still used egg crate on my tank coz it's cheap as chips anyway, and peace of mind is priceless!

 

[Tizer]

Just buy some egg crate for £5, stop fannying around and be done with it. Mind.At.Rest