Timeframe For Phos Leaching

[CStrickland]

Hi chemists!

I'm upgrading to a larger tank, and trying to clean up the new mined dry rocks to minimize algae blooms and smooth the transition. I have juuust enough space to have both tanks in operation concurrently (once I get the Christmas tree out to the curb). I plan to get the new tank scaped dry, add some of my coral-free old rock, and run it bb for a little while to cook out any phos in advance and start building the biofilter.
Once I'm confident the rocks aren't leaching, I'll add sand and tie in the old tank to the new sump for a single water column (slowly, like 10% new water each day). Then start moving critters to their new home.

I got my rocks from reefcleaners, who claim to cook the phos out prior to shipping, and say the rocks won't leach. They have a great reputation, but I'm a cautious person and not in a rush. It will be in the neighborhood of 100# of rock in 75 gallons of water. I use a Hanna ulr

I'm wondering how long would be prudent to cook it myself to be assured it's ready. Like, if the new rocks sit in water for 3 days without raising phos am I good to go, or should I give it 3 weeks?

Also, any other advice about my plan is welcome :)

[shermanator]

You can generally tell within 3 days. I think Reefcleaners rock (and BRS reef saver) are OK to use as delivered, but as you said, no harm in checking...

If you get phosphate leaching, it can take weeks to remove it all (several rounds of removing and then waiting 1-2 days for re-equilibration of phosphate into water column).

[bertoni]

I agree that three days soaking with a powerhead in the container should tell you whether the rock is going to leach. Personally, I'd always check, but it might be clean enough as is.

[CStrickland]

Super. Thanks guys!
Fingers crossed that I won't need it, turns out lots of things our tanks need are stocked in the summer. Seaklear for pools will have to be special ordered, and nobody has bird netting for my screen top until March :( I can get the netting from brs, but lanthanum chloride is pricey to ship.

[bertoni]

You're welcome. Good luck!