Cure time for cement/portland based DIY rock?

I have some new rock made from white portland and aragonite, mostly shelf rock that's about an inch to inch and a half thick.


I've been curing it in a spare old 55g sump on my back porch, it's been soaking for a month or so. The rock was 2 months old before the water curing started. Some was 5 months old (two batches).


I'm facing a new move (earlier than expected) and will need to be setting this tank up a little earlier than I anticipated (about 3 months earlier) if I possibly can.


How do I know that the rock is ready? I'm going to be starting out with weed corals (and, in fact, focusing mostly on hardy softies and LPS anyhow) so I'm not overly worried about the rock being perfect.


Do I just need to check the alk of the soak-water to see if it's drastically elevated?

 

My understanding is keeping track of the alk and pH is how you decide.

 

I can't find the info at the moment but if memory serves 60 days should be enough time to cure the cement. I would definitely test the water to be sure though.

 

Good, thanks folks! I'll test the water.

I'm moving in a little over a week, so I'll test the water tonight, air dry them for a couple days, and then spray paint their edges with some pink and purple Krylon to mimick coralline algae. I've done this on a few smaller pieces and it actually does look reasonably real (better than stark white, at least). A week cure time should be plenty for the Krylon.

 

Sounds good let us know how you do with it. 8)

 

Yor good just check ph and alk, but 45-60 days should be just fine, moving sucks good luck holmes