• Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.

Plexiglass or egg crate?

I

Inquisitive

I want to put something on the bottom of my 55 gallon tank so that the live rock does not touch the glass (my brother had a 150 gallon crack no the bottom and flood the place and he is sure that it was a result of having his rock directly on the bottom of hte tank)...he has recommended I place egg crate down and screen it with mesh (not metal)so that sand doesn't get into the little squares. I was thinking a nice peice of plexiglass laying on the bottom may be better and easier. What do you all think? Where can I buy a piece of plexiglass that will fit and is it cost effective? I'd imagine the plexiglass may be heavier than the egg crate...do you think it will cause any strain on the glass joints? I will have it cover the bottom with a two inch gap in width and 2 or 3 inch gap in length (I don't want the rock touching the sides of the glass either and figure the gap will help insure that I stay in the center of the tank)

thanks!
 
R

REEFLECTIONS

i say egg crate also and forget the plexi glass or screens, but an f.y.i. with all the weight you're gonna put in here, if you do go with the plexi glass don't think twice about the diff. in weight between that and the egg crate...
 
redfishbluefish

redfishbluefish

Officer Emeritus
Officer Emeritus
Egg crate!

First place the egg crate.
Next goes the rock.
Finally the sand.

You don't want the sand supporting your rock. With time, the "diggers" will undermine the rock and could potentially cause for it to go tumbling down. Placing rock directly on the egg crate gives it a solid foundation.
 
JRWOHLER

JRWOHLER

I used cutting boards...you can order starboard cut to the size you want if you are willing to pay the price. I agree though I just couldn't put the rock directly on the glass.
 
Hawkeye

Hawkeye

I've had LR on my old 55 for the past 4 years - no cracks. Rock was placed on glass, then sand.

I didn't do egg crate this go round either - just LR on glass, then sand.

Think of it this way - if LR on glass can cause the glass to fail - every body who has a bare bottom tank is a disaster waiting to happen. ;)
 
redfishbluefish

redfishbluefish

Officer Emeritus
Officer Emeritus
First I agree that rock directly on glass will not cause the glass to crack.

In support of egg crate…rock on glass slides around. If you build a rock structure that has lateral forces involved, you potentially could “push” the rock on that hard, slick surface of glass. By using egg crate, you lock the rock’s valleys and protrusions into the egg crate…gives you a much more stable base. Rock can’t slide on egg crate.

Bare bottom guys are dare devils…they like to live on the edge. ;D
 
JRWOHLER

JRWOHLER

I know it is "safe" ....but I figured given my personal luck if it can go wrong it will so I gave myself that extra margin of safety.
 
I

Inquisitive

thanks guys, I appreciate the advice!!!!

yeah, I figured I'd probably be ok with rock right on the glass too..I know others have done it successfully.....however, being as I own a second floor condo and have good relations with the neighbor downstairs, I want to do everything in my power to guard against any potential floods and damage...

I will do the egg crate....I was figuring on the mesh as a way of ensuring that crap doesn't build up in the squares that inverts may not be able to get too.....I take it this isn't something I should concern myself with then since it was recommended that I don't need mesh?
 
R

ReefBuilderNJ

i would say egg crate. ive heard that the regular egg crate (the kind homedepot sells) made out of plastics leaches phosphates. try to find acrylic egg crates.
just something i heard!
 
N

NYCREEFER

wow, this why I love to read these posts. You learn something everyday. I have the regular HD eggcrate on the bottom, I wonder if that my phosphate source? ???
 
redfishbluefish

redfishbluefish

Officer Emeritus
Officer Emeritus
ReefBuilderNJ said:
i would say egg crate. ive heard that the regular egg crate (the kind homedepot sells) made out of plastics leaches phosphates. try to find acrylic egg crates.
just something i heard!
Click to expand...

I’d be very curious to see the reference articles that incriminated phosphates as a potential leachate out of plastic. If you know of a link, please let me know.

Now, I speak with great ignorance, but I would put phosphate at the bottom of my list of things that could leach out of hard plastic. Actually, it wouldn’t even make my list. I think there are two other groups of potential leachates that are of concern when it comes to plastics….plasticizers and heavy metals.

Plasticizers are typically found in your softer plastics…it’s what makes them soft. I would tend to put these low on my list because the plastics we use in our tanks are hard plastics and contain little if any plasticizer. In addition, I am not aware of their toxicity at the low levels they would leach out. Their carcinogenicity has been well documented, and I don’t know if this is something we need to worry about in our tanks.

Heavy metals are my biggest concern with plastics. Manufactures are actually allowed to put these in their plastics. Because of the recent China-produced contaminated plastics concern with toys, they have developed standards on the permissible levels of heavy metals allowed in plastic toys. Some of the levels are surprisingly high. For the toys, they are concerned about contact transfer/ingestion of the heavy metals. With us, we put this stuff in our tanks where it soaks in water 24-7, probably leaching at some fixed rate. Heavy metals are toxic at very low levels, in most cases ppm, and in some, ppb. If I had the wherewithal of Eric Borneman, I’d be studying the impact of plastics on reef systems. With all the plastics in our tanks, I think it is a potential concern

So I would put heavy metals on my list of concerned leachate that could affect tank life. And top, on my list, are anything plastic from China. Unless I see otherwise, phosphates are primarily coming from food, biological stuff and potentially the water source.
 
JRWOHLER

JRWOHLER

Good question I suppose...so if you use a cutting board do you think it would be safer. I would assume something used for food prep would have to have more controls built in. Of course you know what they say about assuming.
 
qwik

qwik

you can buy starboard (large sections of cutting board material) on ebay. Not all that expensive if you shop around for it . It cuts easy and comes in different colors and thickness.
 
JRWOHLER

JRWOHLER

I used cutting boards for my base I wasn't too worried if they were perfectly matched considering they were buried pretty deep.
 
redfishbluefish

redfishbluefish

Officer Emeritus
Officer Emeritus
JRWOHLER said:
Good question I suppose...so if you use a cutting board do you think it would be safer. I would assume something used for food prep would have to have more controls built in. Of course you know what they say about assuming.
Click to expand...


I am very suspect of ANY plastics material that comes out of China. Having worked on a joint venture in China, I could not get “clean” plastic material from them.

Otherwise, if buying cutting board material, just make sure it does not include antimicrobials. Some plastics in the food industry have these included.
 
You must log in or register to reply here.
Top