View Full Version : useing concrete slabs in tank. worried about rebar.

08-04-2003, 04:00 PM
I'm planning on buying a 180 gallon here pretty soon as my 55 is way overcrowded and two of my oscars are acting like there prepareing to spawn.(locking lips, running the chins on a piece of slate, haveing this shimmy motion with there fins, digging holes in the gravel, and of course practically pinning a pacu 5 times there size and another oscar to the side of the tank)

I'm thinking of tossing a couple of my smaller cichlids in the 180g. I have at my house some large pieces of concrete with rebar in them that I could use to make some caves. I would boil the hell out of these pieces on my fish cooker(ironic) to try and kill any bacteria. some of these pieces have rebar through them which I think would look kinda cool, kindof like an artificail reef, but I'm worried about this rebar rusting and contaminateing my water.

my understanding is metal doesn't rust underwater but when oxygen hits it, is this correct?

can this be done?

08-04-2003, 04:59 PM
Concrete will drive the pH up really, really high. I put a few small concrete bricks in a 125g and within a few days it was over 9 pH.

08-05-2003, 11:56 AM
I second the pH rise. It will leach for a long time. As for the rebar I would be worried about that as well. Once again you could have leaching of iron and other heavy metals that you don't want.

I would go by some slate. It will be cheaper in the long run.