# "Plaster of Paris" Decor ...



## yasir

Hi all,

Sorry for posting this thread here, please guide if there is a separate forum to discuss the Water Chemistry ...

I am planning to make some Decor for my Marine Aquarium (92 Gal) from Plaster of Paris. 

My question is: will Plaster of Paris's decor will be safe for the Marine Aquarium and water quality?

Just for you reference, here are the details about Plaster of Paris:

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Plaster of Paris is a type of building material based on calcium sulfate hemihydrate, nominally CaSO4·0.5H2O. It is created by heating gypsum to about 150 °C.

2 CaSO4·2H2O → 2 CaSO4·0.5H2O + 3 H2O (released as steam).

A large gypsum deposit at Montmartre in Paris is the source of the name.[1] When the dry plaster powder is mixed with water, it re-forms into gypsum. Plaster is used as a building material similar to mortar or cement. Like those materials plaster starts as a dry powder that is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after drying, and can be easily manipulated with metal tools or even sandpaper. These characteristics make plaster suitable for a finishing, rather than a load-bearing material.
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Thanks in advance,

Yasir.


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## Cody

This came out to me...



yasir said:


> When the dry plaster powder is mixed with water, it re-forms into gypsum. Plaster is used as a building material similar to mortar or cement. Like those materials plaster starts as a dry powder that is mixed with water to form a paste which liberates heat and then hardens.


I would definatley not use it if poeple use it to build bigger things. It also says it turns to gypsum in water, which can be bad. That is the stuff that is used in drywall, if I am correct.


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## iamntbatman

Yep...I think the plaster would definitely fall apart underwater, not to mention sending your pH, KH and calcium through the roof.


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## yasir

So, instead of PoP can I use white cement? 

there must be someone who has created rocky look decor at home ... what do you gurus use??

TIA,

Yasir.


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