Curing rock.... how do YOU do it?

[+FluxCapacitor]

Hello everyone,

I recently picked up some dry rock from a member here on the forum (thank you!). I have begun researching how to cure it and have found a few methods to be the tried and true ways that people are doing it. I have a few questions and I wanted to ask the local community at the same time as getting a thread created to help others in the future. I know there is a ton of information available online but I like "non-speculative" concise and organized information when I'm trying to do something. With that said, I'd like to hear what everyone's experiences are with curing rock and what method they used when doing it at their own home.

The two main ways I've read about are:

1. cycling the rock w/ some live rock for a few weeks in a dark container and some heater/water movement.

2. muriatic acid to break down the outer layer of the rock.

I realize that the main thing you're trying to avoid is getting any type of non reef safe thing going on in your system. This includes bad chemicals like anything from an acid wash that wasn't properly cleaned off or excessive phosphates from dry rock that wasn't properly cured. I'm leaning a bit more towards the natural method of just letting it "cycle" in a plastic bin for a few weeks. I was given some rock that was covered in purple algae that I'd like to preserve as much as possible. I know the acid bath will kill this off completely so that's why I'm leaning towards cycling all the rock in a tank.

My question for this is, if I decide to go this way, am I just looking for the nitrate/nitrite levels in the water to even out?

Will adding a bacterial supplement like TurboStart aid in the dry rock cycling much faster?

How will I know for sure when the rock is safe to be added into my tank?

Any help is greatly appreciated and I hope that this thread eventually helps someone else as well.

[jolt]

With a lot of dry rock you are also looking for phosphate to leach out of the rocks. I ran my pukani dry rock in a tub with a skimmer and a GFO reactor. I did not acid wash it.

[Dan H]

I just threw mine in the tank with the rest of the live rock and let it cycle until the nitrates were almost 0. It took about 3 weeks. I was running the skimmer and GFO as well.

[Juiceman]

I just got done researching the same thing.

You can cure it with RO or Saltwater. Just depends on what you're goal is.

If you want it in the tank as fast a possible, then cure it and cycle it at the same time via salt water, skimming, etc.with some live rock or bacteria.

If you just want to rid it of the Phosphate then you can use RO water and soak.

I was going to cure it with Salt water along with a few rubble pieces for a month or so, doing water changes 1-2 times a week.

[Juiceman]

You're looking for the Ammonia and NItrites to be at 0 or close to it, and the Phosphate to be at 0 or close to it. The longer it goes, the better.

[FarmerTy]

You're really looking at ammonia and nitrite to be zero guys, not nitrate. Once ammonia and nitrite hit zero, you've developed the proper nitrifying bacteria you need to start maintaining corals and fish. At that point, you'll have a higher concentration of nitrate in the cycling container as the nitrifying bacteria will have converted all the nitrite and ammonia to nitrates. Most will then move the rocks to the tank at this time. If you are cycling the rocks directly in the tank, then do a full water change to remove nitrates from the water and you should be fine to start SLOWLY adding livestock, allowing for the bacterial population to adjust after each livestock addition.

Just to clarify, curing is mostly regarded as putting the rock in any type of water, RO or saltwater, and allowing for the dead organic material to break down and fall off the rock. Cycling is when you put it in saltwater and allow it to grow nitrifying bacteria by adding an ammonia source, whether directly or by the dieoff off the rock, to develop nitrifying bacteria to be able to support livestock.

If the rock you got is truly dry, the purple coraline algae is already dead so I wouldn't concern yourself with preserving it. Honestly, I despise coraline but that's because it uptakes Mg, alk, and Ca and takes that away from my SPS and also scraping it off the glass is no fun either but that's a whole different subject.

Some have mentioned potential phosphates leaching from the rock you have. As you have mentioned about the muriatic acid, the goal with the acid is to dissolve the first few millimeters of rock because if phosphate had bound itself to the rock, it will be in the first few millimetres. Dissolving it away will release the phosphate and allow you to remove it when you dispose of the acidic solution as well.

Other ways to do that that have also been mentioned is to run GFO in a reactor in the cycling container to remove phosphates and allow the rock to leach any bound phosphates over time. This is not an immediate process but appears to occur quickly for the most part. Another method is doing Lanthanum chloride in a filter sock (10 micron filter or less) in the cycling container as it will rapidly remove phosphates as well. Soaking in RO can work too but is the least aggressive and slowest method of removing the bound phosphate.

To cycle quicker, yes, you can use any type of bottled nitrifying bacteria to help jumpstart it.

[FarmerTy]

I should say I'm in the no skimmer camp for cycling rock as I prefer the organic material to stay in the water to breakdown and create more ammonia to feed the nitrifying bacteria but that's been one of those long debated topics that has people on one side or the other.

[FarmerTy]

Also, to answer your questions directly.

1) You will see an ammonia spike initially, then a nitrike spike following it as the ammonia gets converted, then finally a nitrate spike. When you have no detections of ammonia and nitrite, then your rock is cycled. Nitrate is irrelevant at this point even though you will have a higher concentration in the container as it is the end product. Technically, you could leave it even longer and allow for denitrifying bacteria (not to be confused with nitrifying bacteria) to eventually break down the nitrates but that requires sub-oxic areas to be in existence in your rock and I don't think that happens very quickly in newly cycled rock. That's why most just do a full water change afterwards to remove the nitrates from the water or if you are cycling in a different container, just move the rocks to the tank and leave the nitrate heavy water is behind as it does not bind to rock like phosphate does.

2) Yes, any nitrifying bacteria supplement is helpful to seed the rock or like others mentioned, you can place some other live rock in there and accomplish something similar. If you do seed it with bacteria in a bottle, make sure you follow instructions on the bottle, which usually mentions not running a skimmer for a few days to allow the bacteria time to establish itself or you risk skimming it all out.

3) Rock is safe to add when you cannot detect ammonia or nitrite anymore.

[+FluxCapacitor]

Great tips and I'm sorry I forgot to say thank you. I did read all of the posts before but probably had an emergency come up at work.

What I've decided to do is put all the live rock in a 20G tank I have and run it w/ the heater on 84 and a venturi on the powerhead sucking in air. It's bubbling the water really well right now and the water is pretty warm. My concern was the phosphates that would leave the rock. I also read that some people saw phosphates leach up to 6 months after starting to cure their dry rock.

* I ordered some lanthanum chloride that will be here tomorrow.

* I'm going to dose the rock/crappy water with it.

* 2 days later I'll change the water 100%.

* 2 days after that I'll check the phosphate and dose again as necessary.

My entire goal here is to not use an acid to cure the rock and also not use a ton of salt water doing water changes. Our 12g tank currently isn't large enough to produce any sizable amount of waste water during a water change. The dry rock is curing in about 13G of water right now so it'd take a while.

[+FluxCapacitor]

..... or should I just be using RO water for this? The goal is to get it ready to put in the tank ASAP.

[FarmerTy]

I'd use saltwater, add bacteria in a bottle to help quick cycle, no water changes, and throw a pump in there to keep water circulated.

I'd check phosphate levels after 2-3 days in the water, if high, I'd use lanthanum chloride or GFO to start stripping phosphate from the water. If using lanthanum chloride, I'd drip it in a 10 micron or smaller filter sock. You can find them on eBay for a reasonable price.

[+FluxCapacitor]

Oh I'm sorry, I should have been more specific. I'm using a pump that blows bubbles and water from a skimmer I had. I'll update later after I get the lanthanum chloride today.