Adding dry rock to a tank with already cured rock.

[gallin]

I have a tank that has about 9lbs of rock that I got from an LFS that had been in a tank for sometime and has nice growth on it. After putting it in my tank and letting it set for a few weeks now I decided that I needed more rock. I placed an order for 15lbs half fiji and half pukani rock. Last night I washed all of the new rock off with hot water. Then I put it in a bucket and dumped boiling water on top of it and let it set for about a half hour. I then washed it off again and place it in a bucket of saltwater that is setting in the sun today. (Hot Alabama sun). What else do I need to do before I place it in my tank? (P.S. the tank has a few snails and hermit crabs in it)

 

[cmcoker]

Is there livestock in the tank? Can have ammonia spikes from the pukani, the structure of it allows dead things to be in it that will decay. The pukani has a reputation for leaching phosphate, I put it in a bucket with a powerhead and use lanthanum chloride to drop the phosphates. When it stops leaching, then it can go in the tank.

 

[redfishbluefish]

Sounds like you have a small tank....or the other argument is that you're more than doubling the amount of rock in your tank.....I'd have concerns.

Rock is like a box of chocolates (were did I hear that before), you never know what you'll get in the way of nitrate and phosphate dump until you begin to cure it. I'd either cure the whole lot on it's own, or very slowly start adding a rock at a time (or if small rocks, a couple) and see what happens to nitrates and phosphates as it cures. Have water ready to do water changes when needed. Also keep an eye on ammonia if your current load of bacteria can't handle the dump of ammonia that could/would happen.

 

[gallin]

Would I be best off to let it set in the bucket of saltwater it is in now for a week or more doing water changes every few days? Maybe adding a few rocks a week to the tank? Is there a way to pull the phosphates out of the rock?

 

[gallin]

Is there livestock in the tank? Can have ammonia spikes from the pukani, the structure of it allows dead things to be in it that will decay. The pukani has a reputation for leaching phosphate, I put it in a bucket with a powerhead and use lanthanum chloride to drop the phosphates. When it stops leaching, then it can go in the tank.

There is just the snails and hermits in there right now. So not too much as far as livestock goes.

 

[redfishbluefish]

It's called curing....and it's the death from within that needs to degrade and leach out....and what we monitor is nitrates and phosphates to gauge when the cure is done....typically a month or two, dependent on how much death was in the rock.

Don't need light, but do need temperature and flow.....and water changes when N and P get high...to continue to allow the gradient for leaching out.

 

[redfishbluefish]

Oh....you were typing while I was typing. If only snails and crabs, I'd take the chance and just throw the rock in and let it cure in the tank. As mentioned above, monitor N and P and ammonia.

 

[cmcoker]

Would I be best off to let it set in the bucket of saltwater it is in now for a week or more doing water changes every few days? Maybe adding a few rocks a week to the tank? Is there a way to pull the phosphates out of the rock?

You can use lanthanum chloride(LC) , it's a liquid you add to the water. Phosfree, iirc, is a brand you can get at pool supply stores, there are liquid phosphate removers you can get for aquariums but they are usually more expensive and more dilute. The LC binds with phosphate and drops it out of the water as a solid precipitate, so it's better to do in the bucket. You can do water changes but the LC is less labor and probably cheaper. I'd test the water that's there now to see where the po4 sits currently.

I'd also check ammonia for a couple days, to see if you have decay going on from the rock.

There are some long threads on using lanthanum chloride to cure pukani, I'd give those a read. But whenever i have upgraded tanks I order my pukani rock first and start curing..