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petes
06-23-2003, 2:14 AM
Hey everyone,
I found these cinder blocks in my friends backyard and it looked like it would be great for my african cichlids to play in. The question is, is it safe? I tried researching on the net about whether it was okay or not but I can't get a definite answer. It seems the majority says that if its cured it will be okay and I'm assuming that its been in the backyard for many years probably but I don't know if that counts because it was not submerged in water. Also, I hear it will raise pH quite a bit, but possibly only newer cinder blocks. I don't really want it raise pH and kh because they come out high enough from the tap as it is. I have a piece in a bucket right now and I'll check the pH tomorrow to see if theres a drastic change. Like all of you, I don't want to wake up with a tank of dead fish, and from what I've read that was the situation for a few. Suggestions anyone?

RENEGADE
06-23-2003, 3:54 AM
they have ALOT of lime in them suck the mostrare(sp) out of your hands fast, i don't know if that would mess with your water

Matak
06-23-2003, 6:28 AM
Don't do it!!!

I put some rocks bound in mortar early last year. The lime and other chemicals in the mortar (which are similar to those found leaching from concrete block) really stressed out my fish.

If you thoroughly coat the blocks in aquarium safe epoxy they should be fine. Be sure to let the epoxy cure for at least one week.

HTH :)

Rocketman
06-24-2003, 2:53 PM
And, from watching Old School, I learned that a concrete cinder block weighs 30lbs.

Make sure you factor that in too, if you do decide on using them.

Matak
06-24-2003, 6:03 PM
True, Rocketman, but wouldn't it displace about 20 lbs of water anyway?