Looking for Coral or a substitute


New member
I'm still researching the construction of a 3-4 foot deep tank.

What I'm looking for is some larger pieces of coral rock that I can use to experiment with some reach extension tools so I can place them in a deep tank and be able to manipulate them should the need arise once the tank is in operation.


Where can one locate some coral rock that does not have any living material on it? The reason for this is that I'm going to conduct my experiments in a pool environment and the chlorine will surely kill anything living on the rock, hence no need to pay any premuim.

Are there similar density rock substitutes that might be cheaper and easier to obtain?

Also, what would be the largest piece of coral one would put in a 48 x 30 x (3' to 4') tank?


COMAS Rocks!
Well, you could always obtain some limestone and play with that. It'll be more dense than the typical live rock, but would be alot cheaper than buying dry "coral" rock.

As for largest piece of coral to put in, don't think it would matter, most corals can be trimmed as needed if they get to large. You have to consider most the frags people put in much much smaller systems will still grow colonies upwards of several meters in length. A typical frogspawn can reach 3 meters or so in the wild, granted this is probably several colonies together but from the original parent colony. Same with acro's and porites, ect. ect. ect., they all grow large in the wild cause they don't have pesky reefers fragging them to keep em small. other species, such as toadstools can reach diameters sizes larger than that thank is wide so you may want to consider that into your selections, but again, they can be fragged once too large.


Premium Member
I would not want to own a tank that deep. Especially not for my first salt water tank. Only tank I have seen that looked good with that depth has a bunch(10) of 1000w halides.


COMAS Rocks!
I agree, the lighting costs per month would be more than I'm willing to spend. But to each their own. Just be sure Vic, to research lighting needs, surface area limitations, stuff like that. I definalty want to see photos and a tank log when you get this underway!


New member
I would look for dry base rock. It is usually the same density and weight as LR but no living creatures, and significantly cheaper. Plus, when you're done with your test you can always use it as base rock in the tank.

Or maybe not - I forgot about the chlorine - at least it will look nice in the garden.


New member
Great responses . . . .


The size of rock question goes more generally as to how one "designs" a reef using coral rock. I would imagine that one would put larger pieces on the bottom and build up a mini-mountain in the tank putting progressively smaller pieces towards the top.

Any rules of thumb as to how the reef gets designed? That is why I gave a cross sectional area in the original post.


A couple of you mentioned dry rock . . . where would one look for this? I live in Houston. Is an aquarium store the only place to find coral rock? The local store here charges almost $7 per pound for cured live rock.

Does anyone know what the approximate weight density of coral rock is?


Yes, lighting (and the resultant dedicated power) will be a major consideration. I've just scratched the surface researching this issue. I've gotten several opinions, but no good statistics on how the lighting must perform and what inverts need what strength of lighting level.

I'm considering doing some external lighting from the sides near the bottom since two sides will be against a wall.

Any detailed information as to what inverts require what specific measure of lighting?

BTW, papagimp, what is a tank log?


COMAS Rocks!
A tank log is simply a record of your tank's progress here on RC. A thread dedicated to your reef tank....with lot's of photo's :D

1st: Use your imagination with aquascaping, there are literaly thousands of various ways you could go about doing up your reef, and alot would depend on the look you want to recreate, there are many different areas of a reef and all have different types of flow, lighting, ect. Just be creative. I personally like to have large rocks on bottom, large rocks on top and misc smaller pieces to fill in the gaps as needed.

2nd: dry base rock is in no way similar density to normal live rock you'd buy at the LFS. It's much more dense. I found most of mine locally here from a fellow reefer, but you could look into places that sell stones, rocks, ect. garden supplies, landscaping, places like that. But you can buy dry base rock online at many places, including thatpetplace.com and marinedepot.com

3rd: Lighting will all depend on the various species of inverts and fish you wish to keep. While it's not as imporatant with the fish, some species will not fair well in brighter lights (deeper water fish for the most part) And the inverts, there are just as many different lighting needs as their are inverts. But for a tank that deep, probably going to have to look into something well above a 400w MH system. Those are what I see recommended for tanks about 30" deep. So for 3-4', I could see one needing to use a couple 1000w setups. But again, that would depend on how you layout your corals, the species of corals. YOu could have higher light guys in the upper 30" of tank space and use alot lower light corals for the lower area's. For the most part, Acropora's and simlar stoney corals will require the most intense lighting, while others such as typical run o' the mill mushrooms will require the minimal. And then their are nonphotosythetic that won't require any, but require multiple daily feedings to survive.


New member
You could get some... "tufa rock" i believe it's called.. its a little more dense than most LR you will get but it's close and makes good base rock afterward.

Don't worry so much about the Chlorine if you want to use any of it for base rock afterward either, just throw it in some RO/DI water with dechlor for a few days and it should be fine.