Curing DIY Rock

[johnnyphish]

I recently bought some DIY rock from an individual. (I'm setting up a new reef tank, which will involve new rock + established rock from an existing system.) He told me it is made of cement, sand, crushed oyster shell, and salt pellets. He said it would need to be cured, and referenced a method involving brewer's yeast. Otherwise he said it would drop my pH.

Thus far I have been soaking it in a 20 gal aquarium, in dechlorinated fresh water, with a powerhead. Indeed, my pH has dropped from off the scale (9.0+) to ~7.6.

Does anyone have insight into how to properly, and expeditiously, cure this type of rock? What's this about brewer's yeast? I couldn't find any reference to curing with yeast anywhere.

Thanks!

 

[JTP424]

Did you purchase this from someone on the forums? I'd be curious as to other success stories from them using this...
Not saying it won't work just not familiar!

 

[johnnyphish]

Did you purchase this from someone on the forums? I'd be curious as to other success stories from them using this...
Not saying it won't work just not familiar!

No, it was from an individual here where I live.

 

[Mr. Mojo Rising]

Its been about 20 years since I made my own rocks, but its just a waiting game, change the water every few days to make it go faster. I think I let them soak about 2 months.

 

[afboundguy]

I have been researching making my own DIY rock and haven't done it yet but everything I've read said it takes over a month with daily water changes and to test it test your original water's pH and once that pH doesn't change once rocks in it, it is cured.

 

[twentyleagues]

I used to make agracrete it does take some time and lots of water changing. It wont lower your ph if its not properly cured it will raise it along with alk and calcium possibly to a lethal level. The first couple water changes I did on a background I made ph was over 12 alk was in the 20dkh range. It can also increase phosphates. I have never heard of using brewers yeast not sure what thats about or how its used. Muriatic acid or even vinegar will also help cure it, be aware that using acids is dangerous and will possibly dissolve some of the rock. The following times I made it I used acid and it cut curing time to a couple weeks.

 

[Fish Fan]

As mentioned above, DIY rock using cement products will be very, very alkaline in pH, and need to be soaked in freshwater for several weeks to months. A mild acid in the water will help it go faster. Unless I'm missing something, brewer's yeast feed on starches, so I don't see them having any effect here.

Good luck!