Cinder blocks as tank decor?

[kpea43]

Has anyone ever used a concrete cinder block inside an aquarium. Looks like it could be a neat little piece for fish to swim through . Don't know if it's harmful. Has anyone done it before ?


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[J.Mcpeak]

Hmmm, cement is extremely alkaline! (It burns your skin when wet)
Not sure! Try it first in a bucket. (PH test before and plus 24hrs)

If it changes, use a pond sealer varnish (comes in clear) and be liberal in its application, douse that sucker! Then it will be fine.

 

[ExoticAquarist]

I agree. I thin it would do awesome for a big cichlid or something.


Aquariums make for a betta world. Wanna discus it?

 

[Mebbid]

Hmmm, cement is extremely alkaline! (It burns your skin when wet)
Not sure! Try it first in a bucket. (PH test before and plus 24hrs)

If it changes, use a pond sealer varnish (comes in clear) and be liberal in its application, douse that sucker! Then it will be fine.

Live rock is fairly commonly made using cement. The rock will eventually cure and the pH will stabilize with it if you change the water enough. It's a multiple month long process, but it can definitely be done. I would be worried about the coating on it if it's uncured. If something happens to that coating it could potentially be a nightmare for your tank.

 

[BBradbury]

Has anyone ever used a concrete cinder block inside an aquarium. Looks like it could be a neat little piece for fish to swim through . Don't know if it's harmful. Has anyone done it before ?


Sent from my iPhone using Aquarium Advice

Hello k...

You could. Cinder blocks are made of sand or gravel. The same thing that's on the bottom of most fish tanks. My neighbor has a large pond and he uses cinder blocks in the water to support potted water plants. If the aquarium is large enough, the blocks should be fine in the tank water.

B

 

[Mebbid]

Hello k...

You could. Cinder blocks are made of sand or gravel. The same thing that's on the bottom of most fish tanks. My neighbor has a large pond and he uses cinder blocks in the water to support potted water plants. If the aquarium is large enough, the blocks should be fine in the tank water.

B

Seriously?

Fresh concrete has a ph of around 14. Its powerful enough to seriously burn you. Its also enough to crank the ph of an obscene amount of water to 10+.

Saying "it'll be fine" is ignorant. Its almost like you want people to kill all their fish.

 

[Dallascowboys16]

Seriously?

Fresh concrete has a ph of around 14. Its powerful enough to seriously burn you. Its also enough to crank the ph of an obscene amount of water to 10+.

Saying "it'll be fine" is ignorant. Its almost like you want people to kill all their fish.

yeah, I would for sure PH test that thing first and then use some Pond safe varnish. Then you can put in your tank. Ive seen an article in my favorite aquarium magazine about a guy in Germany with a huge Tropheus fish room and he used tile for the substrate, (flat tile silicones to the tank) with cinder blocks and bricks for the rock work. pretty neat idea for some large cichlids.

 

[Delapool]

I've used the bricks that are made as full of holes (not sure what they are called ) so crayfish had places to hide. Worked well. No issues. Not much testing done but the crays were carrying eggs ok.

 

[icydeath]

I've used the bricks that are made as full of holes (not sure what they are called ) so crayfish had places to hide. Worked well. No issues. Not much testing done but the crays were carrying eggs ok.

They key part of Delapool's statement is they used bricks which are made of clay and shale, clay is inert while shale presents a problem when uncompressed. In the instance of a brick, it is heavily compresssed and non porous thus eliminating the problem with using bricks.

The difference is that a cinderblock is made of cement which has a high pH like others have stated. I would do what was previously suggested and "cure" it as if it were dry rock

 

[Mebbid]

I've used the bricks that are made as full of holes (not sure what they are called ) so crayfish had places to hide. Worked well. No issues. Not much testing done but the crays were carrying eggs ok.

The bricks aren't generally made out of cement so aren't going to have a huge effect on ph. Cement will though. It can be used even when it's not sealed, but you have to thoroughly cure it first.

 

[Delapool]

Well, this is handy. I may learn something on cinder blocks. I'm not sure if I have a cinder block correct. Apologies if not.

I've put a link below to describe what I mean. Like the centre pic on the left in the link but holes were a little larger (or same size and crays were smaller than I remember). Blocks were grey colour so I'm assuming concrete. How they were made I don't know.

As well as this there were other coloured bricks. Grey bricks were rougher, I didn't like using them.

It was basically anything I could find but I can't remember where I got the bricks from. House had been built around 4 years previously so may have been spare bricks stored in garage.

Now I'm kind of wondering on leached metals or chemicals. The only thing that may have saved me was every filter had carbon in it.


http://www.superbricks.biz/pressed_concrete_hollow_bricks.php

Anyways if I did this again, I assume all concrete made stuff has to cure? How long does it take and do you just know from ph stabilising?

Any risk with other chemicals leaching? Also I would go around the building sites or hardware - are all concrete made products the same problem? Thanks in advance.