# Thin set mortar for aquarium?



## joker1535

I wonder if it is safe to mud my Styrofoam background with some thinset mortar. Has anybody tried it or have any comments?


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## pistolpete

I'm a tile setter, so I know my thinsets. I'd recommend against it. Thinsets have a variety of additives to increase working times and flexibility. Most of these are not safe for fish. The acrylic polymers in particular are not good in tanks. Also thinset is a concrete product containing portland cement and sand. It would require extended wet curing to leach out the alkali components or your PH would go through the roof.

If you want to proceed along these lines try Sand mix or mortar mix which has fewer additives, but still all the problems of a concrete product. You should look into epoxy mixed with sand to achieve a similar look.


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## taureandragon76

here are some links to some backgrounds and how to coat them with concrete products.

Make Your Own Background From Styrofoam (DIY DECORATION PROJECTS)
DIY - Aquarium Background


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## Mferko

taureandragon76 said:


> here are some links to some backgrounds and how to coat them with concrete products.
> 
> Make Your Own Background From Styrofoam (DIY DECORATION PROJECTS)
> DIY - Aquarium Background


awesome, bookmarked
they didnt mention though the concrete/lime leaching, does that not happen with a special kind of concrete?


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## taureandragon76

In the first link it explains about how to cure it. I think it's all depends on what mortar you are using. I know it can be done as all kinds of people on the net have done it. Do a google search of DIY styrafoam backgrounds and you will get all kinds of info. You can also use potable epoxy, just gotta be careful with some products as they will melt the styrafoam.


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## Hydrocynus

what do people do in asia that have big tile ponds that almost seem like a swimming pool?
are they coated with some kind of clear coating? I've seen some with several arowanas and high priced fish


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## pistolpete

pretty much everything leaches out of thinset and other concretes after a couple of months and a dozen water changes. I'll bet nobody sticks an aro into a brand new pool.


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## ncutler

For those looking at DIY backgrounds, make sure you are aware of UGL Drylok, Canadian Tire and Home Hardware have it. It is a Ph neutral alternative to cement and can use iron oxides for tinting, but it's 3x the cost.


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