A Guide - Live rock; Curing & Cooking, and Tank Cycling

[Myka]

If you would like to comment or ask questions you can find the original thread here:
A Guide - Live Rock; Curing & Cooking, and Tank Cycling (Original)




Introduction

The purpose of curing live rock is to allow the rocks to shed the matter and organisms that have died during transport, and the matter and organisms that will die due to not being able to live in captivity. This can be done in the aquarium or (preferably) in a Rubbermaid.

Cooking the rock takes this a step further. The purpose of cooking the live rock is to allow the rock to leach the nitrates and phosphates that are in the rock due to the matter and organisms dying in the curing process or which the rock has absorbed from being in dirty waters.

Without cooking the rock your cured rock will leach these nitrates and phosphates into your aquarium where they will mainly help to fuel nuisance algae growth. This is why we often see nuisance algaes in tanks that are under 1 year old. Some people call this "New Tank Syndrome" without really understanding what is happening. NTS (imo) is merely a flux of diatoms during and/or shortly following the cycling of your tank. If you experience diatoms at any other time in your aquarium's life refer to A Guide - How to get rid of Hair Algae (link below).

Other people refer to NTS as the flux of several different nuisance algaes that are "expected" in the first year of your aquarium's life. These algaes are only "expected" because it's about you learning to maintain your particular tank the way it needs to be maintained. For this reason, I would prefer to call it "New Tank Keeper Syndrome" in which case novice and seasoned reefers are both susceptible to. Every tank is a bit different, and you will see nuisance algaes when you are beginning to unbalance the system. The system will always balance itself, thus if there are excess nutrients it will grow nuisance algaes to absorb the nutrients. The leeching of your live rocks can add to the challenge, or you can help alleviate this issue by cooking your rocks first.

I would like to stress the importance of using RO/DI water of 0 tds from the very beginning no matter how you choose to cure your rock.

I would strongly suggest cooking any dry rock sources. These rocks were live at some point, and often have quite a lot of trapped phosphates in them. Once you wet them again the phosphates will leach out just like uncured live rock. A fantastic source for dry rock is www.bulkreefsupply.com 's EcoRox, and don't worry about shipping and brokerage - check out their policies!


Related Links:
A Guide - How to get rid of Hair Algae

[Myka]

Curing in the Aquarium aka Cycling your tank

Many people cure their rock in their aquarium. Your rock will shed bits of detritus as it cures which you don't want to get all mingled in your sand. So, it is best if you do not add your sand until your cycle is over or most of the way over. While your rocks are curing in your tank you should not turn on your lights, and you should not have any fish, snails, hermits, or anything else in there. Be sure to have a few powerheads in there with plenty of flow, and use a turkey baster to blow the detritus off the rocks twice a day during the entire curing/cycling process. Be sure your salinity is 1.025-6 and your temperature is around 78-80 as per usual reef quidelines. When curing in the tank it is best to have your skimmer running right from day one. Check the collection cup regularly as it may fill up rapidly in the first couple weeks.

To monitor the curing (often called cycling the tank) you need to check the levels of ammonia, nitrite, and nitrate. Even if you’ve bought previously cured live rock, you should still follow this process anyway as it is likely there will still be a small cycle. At first, test the water every day for ammonia until the ammonia drops to 0 and stays there for 3 days straight. If the ammonia goes above 2 ppm do a 75-100% waterchange right away to prevent the high ammonia from killing off beneficial life on your live rock, repeat whenever the ammonia goes over 1 ppm (or even better do waterchanges if it goes over 0.5 ppm). Feel free to do as many waterchanges as you want...go ahead and do 50% everyday if you feel so inclined. This will increase the biodiversity on the rocks that survive the cycle.

NOTE- it is a myth that doing waterchanges will slow down the cycle. The reasoning behind that myth is that you are removing nitrifying bacteria in the water column and dumping them down the drain. These are the nitrifying bacteria whose population you are trying to increase as quickly as possible to finish the cycle as quickly as possible. The reason this is a myth is because there is very little nitrifying bacteria in the water column to begin with. The nitrifying bacteria mainly colonize the rocks, sand, and other surfaces. There is a small amount that colonize the water column, but it is not significant enough to slow the cycling process.

After the ammonia drops to 0 you don't need to test for it anymore. You can start testing once or twice a week for nitrite, but you can skip nitrite and just test for nitrate if you want. Nitrite isn't toxic in saltwater aquaria as it is in freshwater aquaria. To clarify:

If testing for nitrite, once nitrite drops to 0 you don't need to test for it anymore either. It may be at 0 when your ammonia gets to 0, or it may take some while yet. Once both the ammonia and the nitrite are at 0 and have been there for a week do a 50-75% waterchange siphoning out as much detritus as you can see including sucking it off the rocks.

If you are not testing for nitrite, wait a week then do a 50-75% waterchange siphoning out as much detritus as you can see including sucking it off the rocks.

In the week that you are waiting to do the large waterchange you can arrange your rocks the way you would like them. Be sure they are secure, and set them on the glass, not on the sand (digging fish will dislodge rocks set on top of sand). Use 2-part aquarium epoxy if you would like. Then add your sand around the rocks. If buying dry sand, rinse it well before adding it to get rid of as many fine silts as possible. If buying “live” bagged sand no rinsing is required. To help ease clouding a bit turn all the pumps and powerheads off while you add the sand, and you can use a mixing bowl or such filled with sand, and lower to the bottom of the aquarium to gently pour it out down there. Once you have all your sand in the tank leave it for an hour, then turn your powerheads and pumps back on . Your tank may remain cloudy for a week or possibly even two. Eventually each grain of sand will get a microscopic film of bacteria around it, and this will weigh the sand down.

Leave your tank running with the sand in it for a week, then test for ammonia, nitrite (if you want), and nitrate. If ammonia and nitrite are both 0 and nitrate is 5 ppm or less, it is time to add a small clean up crew, and further along you will start to add fish. If nitrate is more than 5 ppm you will have to continue to siphon detritus out to lower the nitrate.

Even further along you may start to add corals. But that is a whole different thread entirely!

[Myka]

Curing in a Rubbermaid

Stuff you'll need:

~ Rubbermaid
~ Powerheads (s)
~ Heater
~ Turkey baster
~ Test kits for ammonia, nitrite, nitrate, and phosphate (definately use a high quality test kit for phos)
~ A whole lotta patience

Pick a Rubbermaid container or other container that is food safe, and large enough to put all your rocks in it. Use multiple containers if needed. There is no need to pile the rocks nicely, just cram them in there leaving enough room between them that water can move freely in between. Pick a powerhead that will turn the water over 10x per hour or more. The more movement the better. Use multiple powerheads if need be. Pick a heater of sufficient size to keep the temperature at about 78-80 degrees. Some people like to raise the temperature, but imo this only increases the chances of killing beneficial critters that are already on the rock. Be sure to place the heater away from the plastic of the container as the heater will melt a hole in it! Fill it up with normal saltwater. Turn on your powerhead(s), and be sure there is lotsa flow rumbling through those rocks. Put the lid on the container, and ensure complete darkness 24/7.

Follow the same testing and waterchange schedule as when curing in the aquarium (see previous post). Swish the rocks in the tub to remove detritus before doing waterchanges. Using a turkey baster helps. Be sure to leave the rock exposed for as little time as possible. When the ammonia, and nitrite both reach 0 is when most people will put their rock into their aquariums, this is when the curing process is over.



Cooking the Live Rock in a Rubbermaid

If the live rock is already cured, and you would like to continue on to cook the live rock, continue to do 100% waterchanges once a week. Once your nitrite drops to 0, stop testing for it, and test for nitrate. It may take quite some time for nitrate to drop to 0 (possibly several weeks, maybe even a couple months), but when it does you can then stop testing for it, and start testing for phosphate. Be sure to use a high quality test kit (I prefer Salifert for phosphate). Like the nitrate, it may take quite some time for it to drop to 0. Once it does drop to 0, and stays there for a couple weeks test ammonia, nitrite, nitrate, and phosphate. If all are 0, you have successfully cooked your live rock. Give yourself a pat on the back for your patience, it will pay off!

The only downfall that I have noticed of cooking liverock is the die off of a good amount of coralline algae. I think the benefits of cooking the live rock hugely outweigh this though. The coralline actually comes back very quickly under healthy conditions.