# Corner structure advice



## JerseyBird97 (Sep 13, 2009)

Need some input. I'm making a corner structure from platic crate, cement, sand and rubble to sit in the back corner of my tank. I know it'll collect algae, nitrates, scratch glass... yadda yadda. Any other thoughts? Has anyone done this? Do you think the astetic value outweighs the chemical cons?


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## bettababy (Oct 12, 2006)

The chemical cons will be a big determining factor over what animals can live in that tank, if any... so I wouldn't be too quick to dismiss those things. The list of things you mentioned before your "yada yada" makes a huge difference in life or death of animals, please don't take that lightly.

Scratching glass is not the only concern with the glass. What if you should need to remove this structure at some point? That would be impossible. How much weight sits in a given area of the tank will also make a difference if its overdone, especially in a smaller tank. Too much weight on one end can cause a lot of pressure on the glass and while it may not happen right away, it can lead to future problems such as cracking and leaking.

Nitrates is a huge deal because in high amounts for any length of time it is toxic to all fish and inverts. Algae would be the least of the worries. There are other chemicals besides nitrates, along with many minerals that can cause a lot of harm in an aquarium. 

Texture was not mentioned. Concrete and cement mixes tend to be very rough in texture, which is not ideal for a large number of species of fish. Catfish is a big category, eels, loaches, and even plecos can suffer irritation, tissue damage, sores, etc. from being exposed to a rough surface on a regular basis. 

If you can give an idea of what you are trying to create and what animals are planned to be in the tank, it would be much easier to help with your question and also offer alternative, safer solutions.


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## SinCrisis (Aug 7, 2008)

bettababy said:


> Texture was not mentioned. Concrete and cement mixes tend to be very rough in texture, which is not ideal for a large number of species of fish. Catfish is a big category, eels, loaches, and even plecos can suffer irritation, tissue damage, sores, etc. from being exposed to a rough surface on a regular basis.


Ive seen entire rock walls made from cement and styrofoam, i think a little corner thing will be ok.



What kind of corner structure were you thinking of making? Is it a cave? or just a mountain-like structure? Also how large is it, how much does it weight, etc. Its hard to tell how detrimental such a structure would be without the details. IE. small hollow cave will be far less dense than just a block of cemented stuff, a small cave will be less of a concern vs a large cave, etc.


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## 1077 (Apr 16, 2008)

Might review /Google, content of Portland cement. Is comprised largely of lime which will affect water chemistry if not cured completely or sealed.
Some saltwater folks I believe have utilized cement rubble to create their own coral and perhaps the ability of cement to make water hard is not as much a concern for them as opposed to freshwater depending on inhabitant's?


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## bearwithfish (Sep 29, 2009)

no in salt water cement needs to be cured for a very long time........ and with a few certain methods.. i tried it a few times and some how always messed up the cure so when i tested each batch it was so horrible i would never put it in my tank.... again a lot depends on what you are attempting to accomplish....


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## 1077 (Apr 16, 2008)

bearwithfish said:


> no in salt water cement needs to be cured for a very long time........ and with a few certain methods.. i tried it a few times and some how always messed up the cure so when i tested each batch it was so horrible i would never put it in my tank.... again a lot depends on what you are attempting to accomplish....


 
I would assume that concrete rubble from very old sidewalks ,buildings, would be cured and thus maybe safer?


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## JerseyBird97 (Sep 13, 2009)

this is a mrine tank. I took crate and zip tied at a 90 degree layed it flat and filled in with quickreet and covered with live sand rubble and a small flat peice i had then when that set did the other side. It is completely removable as long as it doesn't break so I can clean back there. I know cement has to cure a week (my dad is a mason).

That's a good point about the lime or lye or whatever crap is in that... I'll have to double. Thought It might work cause I've seen people make rock out of the same stuff. 

Thanks for the input... let me know if ya got anything else.


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## JerseyBird97 (Sep 13, 2009)

...also I didn't mean "yadda yadda" as a brush off I was just impliying I'm aware of the obvious dangers.


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## bearwithfish (Sep 29, 2009)

the cure time in water with changes and at least one or more vinager baths for this to be tank safe is 6 months in water at all times and changes either every day or two.... best with running water i attempted it in 45 days in constant running water and when i put it in a tub with water i tested at 7.7 PH after 24 hours the PH went off the charts 9.9 was the highest i could read and it was much darker than that..... google agrocreat or man made live rock and read a bit more a bout the curing process its not quite like making regular items (stairs and such)


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## JerseyBird97 (Sep 13, 2009)

Thanks bear... so this is pretty much a bad idea... will scrap


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## lorax84 (Nov 3, 2010)

You can also build in tank decor out of Styrofoam and seal it with drylock. Drylock is a masonry sealer used for sealing basements, once dry it is 100% aquarium safe. Cement will take a very long time and cure as bear said. I have never used Drylock but someone on another forum used it for angel fish and turtles. Here is a thread about it.

3D Background with Drylok - Turtle Forum

There is a lot of info on 3d tank backgrounds that I am not even going to try to reiterate.


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