home school live rock project Home School Live Rock Project


This is a lesson plan about creating your own live rock and helping save part of the wild reef. We teach people all the time how to make live rocks and we've done this for years. Thousands of people have made rocks around the world and you can to.

The students are very excited to make their own rocks, and we think you'll enjoy it too. So many people are harvesting live rock out of the ocean and this can't be the best way to preserve the natural reef.

The people who are doing this are only trying to survive and make some kind of income to be able to feed their families; they certainly are not getting rich. Chloe the mermaid said that in other areas she has visited, they bomb the reef or use poison to catch the fish. The animals that live higher up on the reef, the ones that need light to sustain themselves, all die when blasted to the bottom where no sunlight can touch it. The poisons cause also tremendous death and destruction.

Amity the little turtle said I have a great Idea! Why can't we make rocks instead of taking rock? We could make our own live rock and seed it into the ocean so we can make a more solid foundation. There will more places for little coral larva to settle out on. Now Amity is really getting excited. We could teach the sharks to make rock. They could teach the people who kill the sharks and take the live rocks. These new jobs could pay twice as much money as they get for shark fin soup. We can pay them by the pound for the rocks that they make. We know there is a market. because we can see in 6 months how much rock has disappeared.


The Shark's and students can work together as a team they would make more money and our oceans, rivers, lakes, and much more will be healthier. Honestly this is not just for us, but please please think about future generations. We will save the sharks and save the rock and make our dreams for our grandchildren come true.

MIKIE'S BOTTLE ROCKS - Make your own

GARF's newest rock making project is inspired and described by Mikie the Manatee, and it is shared through the hearts of all who enter the Mermaid and Ocean School. This weekend Mikie has planned for all the students who attend the Mermaid and Ocean School to clean each others habitat. Trash seemed to be everywhere, especially during the summer months, when the weather starts heating up and school was out for the summer.

So many visitors come to play at the beaches, yet they tend to forget to follow some of the most important rules of the beach. Rule one is to leave no trash behind, for plastic bags left unattended fly away in the wind and catch around many of the most cherished birds, fish and corals. This often leads to their early demise.


The Geothermal Aquaculture Research Foundation has been making sand molded live rock for many years.  The AragocreteTM and Glue reef project is a way to make reefs from scratch using nothing from the wild ocean. We teach the ZERO IMPACT method of reef keeping. Imagine setting down with an empty aquarium and a clean piece of paper. You can draw any shape of live rock sculpture. You can have sweeping arches and dark caves with multicolored Mushrooms peeking out of them. You can have a forest of Acropora coral branches in many colors growing on top of an elegant overhanging ledge. Your breeding pairs of tank raised marine fish dash into their nests when your guests look into the reef aquarium. They all peak out just in time to hear you proudly say I GREW IT ALL MYSELF, nothing new came from the sea.

It is very important that this hobby does as much as possible
to limit the things we need to take from the wild.
If we can produce most of the reef products we consume
there will be less demand to limit collection of
marine products with new laws.


MIKIE'S BOTTLE ROCKS - Make your own with this link

It is very important that this hobby does as much as possible to limit the things we need to take from the wild. If we can produce most of the reef products we consume there will be less demand to limit collection of marine products with new laws. This project can be done as a small scale at home aquaculture project.

Making a family reef aquarium with children is one of the great QUALITY TIME projects of all time.

The same methods can be used on a much larger scale to produce quality dry base rock for an ocean based live rock farm. Several live rock farmers are now using our method to produce light weight, interesting live rock.

During the last dozen years we have studied most of the available types of rock that could be used for live rock farming. We have tested tons of these rocks in our laboratory. We have also planted these rocks in the ocean in several countries. AragocreteTM and other cement based rocks grows coralline algae faster than any natural base rock we tested. It is very fun to draw a reef aquarium, and then build the shapes of rock you need to make the design you want. This article will show you how to form many beautiful live rocks that can be as porous and light weight as you want to make them. We have made and sold many tons of the dry base rock to both hobbyists and public aquariums all over the United States. GARF is keeping track of many of these reefs so we can add that data to the information we gather from the dozens of reefs we have started here in Boise, Idaho. We have hundreds of reports in our data bank from all over the world. People who learned to make this type of rock on our FREE ONLINE CORAL FARMING SCHOOL at continue to send us pictures of their live rock.

Everyone at GARF is dedicated to teaching as many people as possible to - SAVE A REEF, GROW YOUR OWN. We also promote worldwide reef farming so the native people can earn a good living that depends on a healthy protected reef environment. People will make the needed changes if the healthy reef can produce a steady source of income now and long into the future. It is important to the future of our hobby that we all support this effort by buying aquacultured reef products anytime we can. Ask your local aquarium dealer to purchase and promote aquacultured reef products. I am receiving more and more e-mail sharing new ways that people are making these rocks. If you think of some new ideas please share them with us so we can get others growing their own reefs. Please e-mail us at and we will answer any questions we can.


We will explain the basics in the first section so you can get started making rocks before you read about the more advanced projects we will teach you to do in the second part of the article.


Carib SeaTM aragonite sand in Styrofoam fish shipping box for making mold.
Carib SeaTM aragonite sand for making AragocreteTM
Portland cement - We use grade #1-2 , it is the most available cement for making concrete
Plastic buckets
Small shovel
Fresh Water for mixing AragocreteTM
Fresh Water for washing equipment

We use Styrofoam fish boxes for all of our AragocreteTM production because we want all of our finished product to fit in these boxes when they are ready to ship. We have students make some of the rock. It is human nature to make the AragocreteTM sculptures larger as the day goes on so that you can use up the AragocreteTM mix. When we made the sculptures in large wood boxes we often found pieces that would have been good for standing up and hanging road signs on. Digging up the finished AragocreteTM is the fun part, but it is nice if you can lift them when you get them uncovered.


1. Fill the fish box 1/2 full of Carib SeaTM aragonite sand and dampen with fresh water - the sand needs to be only moist.
2. Dig a hole in the sand that will be the shape of the finished rock.
3. Mix 5 parts Carib SeaTM aragonite sand with 1 part Portland cement.
4. Pour the AragocreteTM into each hole in the mold.
5. Cover the AragocreteTM with Carib SeaTM aragonite sand and wait 2 days before removing it.
6. Soak the new sculptures in fresh water for 6 weeks for the easiest cure,
There are faster ways to do this. It is important that you use fresh cement when you do this project. Several times people have sent us e-mails saying that their sculptures did not dry properly. When they tried to remove the AragocreteTM from the sand molds it crumbled. In each case we discovered that they had used cement that they had from a job several years ago. Cement powder can absorb water from the air and it will not make quality AragocreteTM.

We will describe several types of live rock that you can make. These shapes can be combined to make many different reefs. We use the three legged reef tables to make the bottom layer and then stack the other rocks on top of the tables. This Small Footprint Reef allows you to have a very open structure that only touches the bottom of the tank in a few places. This allows the sand to be exposed to the water flow or the bare bottom to be siphoned.

BASIC SAND MOLDING LIVE ROCK - Making a nice looking rock

STEP 1. Dig out the sand in your box to form the basic shape you want. Be careful not to expose the bottom of the box or your rock will have an unnatural flat spot. Any holes or caves you can make will add interest to the rock.
STEP 2. Place the AragocreteTM mix into the mold hole and insert any sea shells or rocks you want to use 1/2 way into wet Aragocrete.
STEP 3. Cover the rock with sand - a very natural looking rock is made by using different sand on the top of the rock. This will look like the rock was formed in the ocean. We use Carib SeaTM Aruba shells for our top layer.
STEP 4. Allow the rock to dry 48 hours and wash it in fresh water. Your rocks will be much stronger if you cure them in cold fresh water for several week.


More misinformation has been published about this simple process by inexperienced beginners than about any other part of this project. We use CaribSea aragonite and cement because this combination cures very easily. If you use other types of gravel or shells then you should test the pH of the aquarium when you add a small piece of your type of rock. Curing concrete is NOT rocket science. We have used fresh water and vinegar to cure thousands of square feet of concrete in Koi ponds for over 30 years. Many of these ponds house fish that cost more than a 100 gallon reef aquarium. Make some rock, take your time curing it, and have fun. Please do not let any beginners who have never even made their first ton of rock scare you away from this simple fun project.

The name AragocreteTM is used to describe a product that is made using CaribSea aragonite and cement. There are many other ways to make live rock base and it will be exciting to test these products later. As in all of our reports we want to stress that the way we teach people to do things is NOT the only way to do them. We teach ways that work very well all of the time so our students can duplicate our success.

The sand molded rock is allowed to dry in the sand for two days. Keep the sand moist and the final rock will be stronger. Then we cure the new rocks in fresh water for six weeks. This water bath should be changed often. This allows the new rocks to harden and get stronger. We soak our AragocreteTM in geothermal water for several months because we have hot springs and we want our products to be 100 % reef safe. You can speed up the curing by changing the water.


The rock is placed in a grow-out system with good light and water flow. We add some coralline algae that we have scraped from the glass in a healthy reef aquarium. The best coralline algae we grow is in the aquariums that have one 40 watt Actinic one 40 watt daylight bulb. Too much bright light such as you get from Metal Halide bulbs will slow coralline algae growth. The more types of coralline you add at first the better your chance that you will grow a healthy batch of this desirable algae.

STEP 1. Treat the system water with extra SeaChem Reef Builder and Reef Calcium to start the coralline algae.
STEP 2. Before the rock starts to grow coralline algae you can glue several small cuttings to the rock with super glue.
STEP 3. Allow the live rock to finish growing. Watch for unwanted algae and Aiptasia anemones. We use Copper Band Butterfly fish and Reef JanitorsTM in our grow-out systems to control these pests.
We will explain this part of the project in greater detail later in this article.



This type of rock is very easy to make so we will start with them. We have designed some tables that work really well when people are concerned about placing their rock right on the sand. The tables look very natural once they have animals growing on them. They give the fish more hiding places and places to swim through. It also allows a more stable structure on which to place your heavier corals. One problem I have continually fought is the falling over of live rock. Often the corals become too heavy and won't stay where I put them. The tables are a very good permanent foundation for your reef system.

Place a layer of AragocreteTM on the sand that is about ten inches long and five inches wide. Press this down until it is only one inch thick in most places. Make three balls of AragocreteTM that are about the size of a tennis ball, and roll them in your hands like you are making a clay snake. When they are about an inch thick and six inches long stand each leg up on a corner of your new table top. Add Sand around each leg as you place it to keep the leg from sagging into a lump. We like to put one or two holes in the table top by poking a finger though and then pouring in sand to keep the hole open. Cover the entire table with sand and wait 24 hours before digging it up.

SAND MOLDED CAVES - hand formed and rubber glove caves

Hand formed caves can be any size. They are very natural looking, and they make very good additions to any reef aquarium. You start this project with a ball of AragocreteTM about the size of a soft ball. Place it on a bed of gravel and hollow out a hole in the middle of the rock and pour in some Carib SeaTM aragonite sand. This sand will form the inside of the cave. You can increase the size of the hole by pushing the sand up against the sides until they are quite thin. Add more sand until the rock is full and the sand covers the sides of it. Cover the rock with Carib SeaTM aragonite sand and tap on the side of the box about 20 times with your hands. The vibrations will settle the sand into the AragocreteTM. The sand on the outside of the rock will keep it from sagging while it dries. Let the box set for 24 hours before you remove the rock from the sand. Soak the rocks in white vinegar for 12 hours and rinse them in fresh water before you use them.



This project is going to be fun. I am going to show you how to make some great cave rocks using rubber gloves to make the hollow caves. I have been making these rocks all semester and I enjoy digging them up more than any other type of AragocreteTM live rock that I have made. Last Summer as we were finishing the 600 lbs. of 'TONGA BRANCHES' and starting the 600 lbs. of Arches I made my first Glove Caves. These rocks weigh from 4 lbs. to 7 lbs. and they are 7 inches to 12 inches wide. They are very thin walled with 1 large hole and 3 to 5 small holes. No one who has seen the finished caves in the lab has been able to figure out how we made them.

You start this project by blowing up the rubber glove. You can make some very interesting flat Glove Caves by only blowing the glove up with a small amount of air. We use rubber bands to tie the glove closed, and we have reused several gloves. We make a round pancake shaped base of AragocreteTM in the beach box about 1/2 inch thick and place the inflated glove on it to start each cave. It is important to make this base as thin as possible because the desired final effect is a cave with as thin of walls as possible. We often put broken shells and small aragonite rocks in the beach box before we put in the AragocreteTM for the base. These shells and rocks will then be on the surface of the cave base when it is dug up. We then add some AragocreteTM around each finger keeping the end of the finger free of AragocreteTM.



CaribSea Aragonite Sand for Beach Box
CaribSea Aragonite gravel for AragocreteTM
# 1 - 2 Portland cement
Several old sea shells to put in base of cave
One rubber glove for each cave

The hardest thing to do in this project is keeping the AragocreteTM you use for the walls of the cave from flowing down into a pile on the base. You can solve this problem by pushing dry gravel from the beach box up against the side of the cave as you build the walls. When you have added enough AragocreteTM to cover the sides of the cave rock it will be 3/4 buried in gravel. We have been leaving a hole about 3 inches wide on the top of the cave. This opening looks natural because you can make the walls very thin around it. These caves make a great place to hide power heads. We use CaribSea Aruba shells on the surface of some caves and it makes them very bright and interesting. The finished rocks look like fossil sea shells have formed them in the ocean.


1. Mix 5 parts - by volume - of CaribSea Aragonite gravel with 1 part Portland cement to make the AragocreteTM
2. Make a thin base of AragocreteTM in the sand by pressing the AragocreteTM with your hand.
3. Place the inflated glove on the base.
4. Put some AragocreteTM around each finger leaving the ends exposed.
5. Build the walls of the cave by adding AragocreteTM and push the sand up around the cave to hold the walls up.
6. Leave a small hole in the top of the cave, and cover the cave with gravel.
7. Let the cave set for 48 hrs.
8. Dig up the cave and wash it.
9. Amaze your friends, and have fun!!

We have been placing small Mushroom rocks inside these caves in our grow-out systems. We will move the rocks to new caves when the Mushrooms start to grow inside the caves. I am certain that there is a market for 4 lb. caves full of purple, blue, and red Mushrooms. I soak all my AragocreteTM Living Sculptures in fresh water for 4 weeks and I have not had any problems with PH. Be sure to soak the rocks in vinegar or cure them in fresh water before adding them to your systems.

We invented the socket rock and reef plug method of invertebrate culture so we could plug the sps corals into a coralline covered rock that would hold it up as it grew. Many sps coral die because they fall onto other corals. This method can prevent that from happening as often. It is very exciting now that we have many finished reef sockets. I remove the reef plug from them and the colony of inverts has grown onto the rock. It is most fun when a sps coral does this. Then you have a cave with coral growing around it. You then move the plug into the next rock.


Garf's Archives


GARF Home Page



Orders (800)600-6163
Support (208)344-6163
E-mail 1726 Merrill St.

Boise, ID, 83705