Why do we use saltwater instead of fresh when curing rock?

[Cren]

I've recently started curing some pukani dry live rock for a new build. I have the rock soaking in some RODI freshwater for a week(it stinks!) before I plan on draining it all and soaking it in saltwater for a month or two. I was just wondering why we use saltwater for curing? It seems wasteful when it's all going to be dumped but I'm sure there's a good reason for it.

 

Also, would it be harmful to use regular tap to hose down the rock before I start curing with RODI saltwater? I'm in Florida, I believe our water is pretty chlorinated, but with the rock curing for a month or two is it even an issue?

[seabass]

You could. However, people use saltwater to establish saltwater bacteria populations. If you cured the rock in freshwater, it would kill the marine life on the rock. Then after it is cured, you would still have to establish marine nitrifying bacteria populations.

[seabass]

I've even used a pressure washer before. A vegetable brush also works pretty well at removing dead organic matter.

 

I'd probably add a nitrifying bacteria culture after you put them in saltwater.

[tetraodon]

Thanks for the response!

 

So the difference is in the type of bacteria grown. In my case the rock is already dry and dead so there's really no harm in starting to cure the rock in freshwater, correct? I read the first week is pretty bad with this rock so I thought it would be a good idea to dump the first batch of water after a week, which is why I started with freshwater. I will be switching to saltwater in the next few days and I'm sure there's still plenty of decaying matter in this pukani rock to establish the marine bacteria I need... I hope!

 

Would there be any issue spraying the rock/powerheads/pumps with tap water to clean them off a bit before I start curing with rodi saltwater?

rock meant for marine environments will not cure in fresh water. as soon as you raise the salinity you kill off the fresh water bacteria and restart the cycling. you can use fresh water to clean the rocks and its recommended to cut down dust.

[seabass]

rock meant for marine environments will not cure in fresh water. as soon as you raise the salinity you kill off the fresh water bacteria and restart the cycling.

People often use "cure" in a couple of different ways. One is to clean, and the other is to cycle (establish a nitrogen cycle). I believe the OP is using the word cure as to remove the dead organic material. However, we typically use the word cure as to cycle.

[tetraodon]

People often use "cure" in a couple of different ways. One is to clean, and the other is to cycle (establish a nitrogen cycle). I believe the OP is using the word cure as to remove the dead organic material.

clean vs cure, i usually associate cure with the establishment of bacteria. either way hope it was clear enough to understand

[seabass]

Yeah, you used it like most of us do. I posted that primarily for the OP's benefit.