Egg crate

[andrew catling]

I have read about people using egg crate as supports for LV but my concern is,
is it salt water safe?.
I always believed that any plastics used in a salt water set up had to be food grade plastics, ie: ABS, if it wasn't then you risk some kind of leach off from the plastic which would be toxic to the live stock.
I even heard of people using PVC piping the kind you get from B&Q for plumbing and DIY spraybars , now even I know this is not ABS.
All you guys who have used egg crate or plummed in your sumps, made DIY spraybars etc, etc, comments please, whats safe and what isn't

 

[Navarre]

All my piping was from B&Q, the eggcrate is standard eggcrate.
No problems with any toxins at all. I know of many people that use this very tubing with no problems. When you consider the price comparison to the real marine stuff to go in a tank the saving runs into £100s Just make sure you use a glue that is not treated with an anti fungiside.

 

[ostrow]

Eggcrate is widely used and is fine. Not sure I am following LV but I use it to raise my skimmer in my sump (Euro-Reef skimmers need to be in less than 8" of water), others use it to raise live rock off the surface, others use to mount corals. It is widely used.

 

[andrew catling]

Sorry LR not LV, was tired when I sent the post.
Your absolutely right about the savings that are made, ABS is very expensive compared to basic PVC piping.
Think I'll go with B&Q.
What make did you get or was it just bog standard waste pipe.

Thanks

 

[chkltcow]

Don't mean to hijack here, but while you're on the subject of egg crate, I've gotta ask. Why would you use it to support LR? From the people I talked to before starting my tank, there were two schools of thought. One, you put LR in first, directly on the glass, and pour the sand around it.... that way it's supported in case of digging fish so it can't fall over. Or... two.... you place the LR directly on the sand to create an anaerobic zone, which helps cut down on nitrates in the water by converting it back to nitrogen by anaerobic bacteria.

So, what exactly is the egg crate for?

 

[Navarre]

Andrew:
Just bog standard waste pipe mate.
I have the marley push fit pipes (glued for safety) for the overflow pipes to the sump.

chkltcow:
Putting the rock directly on the glass is one way of doing this and it does work however the rock loses efficiency in filtration as the rock can only filter correctly with a flow of water over it. thus a rock with 1/3 of its surface covered cannot perform its function as well.

Putting live rock directly on the sand will cause the sand to go anearobic but this doesnt mean it will definately make a zone to help complete the nitrogen cycle. Sand can produce highly toxic waste in such areas and should this sand get disturbed by moving rocks etc then the toxic waste enters the tank and causes all sorts of trouble. (Hence why i only recomend DSB type sand in sumps where they dont get stirred up so much).

By placing the eggcrate down and rock on top allows you to get a spray bar under the rock. A flow of water can then pass under the rock and this will then give a water flow across 100% of the rocks surface which then means the rock is working at its most efficient manner.

Its estimated that by using the rock in such a way you can (in theory) use up to 1/3 less Live rock in the tank due to a more eifficient flow.

hope this helps

 

[ostrow]

The spray bar argument is one. Some people go bare-bottom and put the rock up on the egg crate to allow flow and cleaning.

The contentions regarding sand beds though are highly controversial. See Dr. Shimek's articles on RC and elsewhere. There is little evidence anywhere of sand beds going anearobic if properly seeded and in tanks properly maintained. And there is no reason to expect a sand bed to do so in a tank properly maintained.

If one is concerned about being able to maintain a stable population of worms and pods, then one shouldn't put sand in a tank.

But I have seen gorgeous bare-bottom tanks in which the rock was slightly raised on an eggcrate platform. Quite stunning.