cement blocks in the reef tank

[zygote2k]

I'm looking for an easy way of bringing up the structure in one of my maintenance tanks. I was thinking about using concrete blocks because they would give me a new flat surface from which to build on. Do I need to cure them in salt water before using them in an existing reef?

[Origami]

I suspect that you would have to cure them, but I don't know that you need to do so in salt water. I would handle them the same way that you would handle curing aragocrete. That is, soak them in fresh water for 6-8 weeks or so, changing the water as needed. You're mostly looking to stabilize the concrete so it's not having a caustic (pH-high) effect on your water.

 

Almon could probably give you specific advice. You could also look up advice on curing aragocrete at www.garf.org.

[paul b]

You can use concrete blocks but cement can lead to problems with the pH. Regular clay bricks are better and cheaper and they are inert. They are also porous and make great live rock. I have used them many times.

[Coral Hind]

Many public aquariums use CMU as a base for the display rock. As Tom suggested, just cure it like any other concrete based product until the PH is stable. Vinegar can be used to speed the process up.

[trockafella]

Never had any issues with my live frames having cement block bottoms..

[jamal]

i am using cement blocks now and my only problem is detritus. they work