Cinder Blocks

[ReefDoberman]

Does anyone know if there are any reasons (chemically) that I could not use a cinder block as a stand for something in my sump? I admit that I actually have done this before without consequence however the more I think about it I thought I would check to be sure.

Thoughts?

 

[ReefDoberman]

To clarify the cinder block would be submerged in my sump water (in a 100 gallon rubbermaid)

 

[jrw]

I don't know the answer to your question, but something to consider is this...

There is a difference between concrete block and cinder block.

Concrete blocks are pure concrete, whereas cinder blocks are made from coal cinders and concrete that form a lighter, cheaper building material.

Just something to think about.

 

[ReefDoberman]

It is the concrete part that I am slightly worried about. I know in most applications when concrete is used (diy liverock, frag plugs etc..) there is a curing process that needs to take place prior to introducing them into your system.

I am not sure if this applies to cinder though... Like I said, I've used it before and didnt have any problems but I would like confirmation

 

[chimmike]

i would use a concrete block and not a cinder block. coal bits may have trace elements of mercury, etc. that could leach out over time.

cure a concrete block for a few weeks, doing a few water changes in the process. That should help a bit.

 

[laugh]

Do they still make cinder blocks?

 

[jrw]

<a href=showthread.php?s=&postid=14833245#post14833245 target=_blank>Originally posted</a> by laugh
Do they still make cinder blocks?

Yes. It is cheaper, lighter, and less compressive strength.

None of that matters for one block used the way he plans, but I might elect the concrete block and cure it until the pH does not seem to change.

Just my thoughts.

 

[BuddhaKiss]

Just out of curiousity, what are you planning to put on top of the cinder block? I ask only b/c I'm wondering if you could make a stand out of eggcrate instead.

 

[captstinky]

My whole tank is DIY concrete rock. Curing instructions can be googled for fresh concrete. I know little about cinder block but all posts seem to be accurate so far. I see lots of cinderblocks in the salt water here with marine growth FWIW, but we aren't talking a closed env't there either. for a couple bucks you could make your own...