Live Rock vs Fake Rock

butts182 · Mar 2, 2011

I've seen some posts recently where people are making fake rock shelves and displays for corals. I think they look great, but what about the bacteria benefits that you are not getting from the live rock? Don't you want live rock, or at least dead rock so that bacteria can grow? If you have this sort of rock, can you just add a bunch of live rock in the sump? Do you need a light on the sump for some of the beneficial bacteria?

mdb_talon · Mar 2, 2011

There is no reason that "live rock" cannot be manmade. If you made it out of dense smooth glass it wont be very "live" for example, but made out of the right materials it can become very "live".

butts182 · Mar 2, 2011

I guess i didn't make my question very clear. Since manmade rock doesn't have holes throughout, will it support much less bacteria growth?

Troylee · Mar 2, 2011

pretty much... bacteria colonization is all about surface area....i my self am not a fan of very porous rock althou you get more bacteria it becomes a trap for garbage and detrius build up....

MH_Courtney · Mar 2, 2011

Rock that is more porous is going to be better for your tank/filtration. If you put rock in your sump it does need some kind of light but it doesn't need anything crazy. I have all fiji, which is very porous, and just use that and a protein skimmer (no bio balls, carbon or any media or reactor) and my nitrates are always at 1 or 0 and i feed the tank very heavily to keep my fish fat and happy.

Troylee · Mar 2, 2011

why would rock in the sump need light???? curious..... bacteria doesn't need light and many people cycle there tanks with no light just to keep the algae growth to a minimum...

MH_Courtney · Mar 2, 2011

Troylee said:
why would rock in the sump need light???? curious..... bacteria doesn't need light and many people cycle there tanks with no light just to keep the algae growth to a minimum...

you are correct that bacteria doesnt need light but if the rock has any coraline or anything like that on it then it will need light to survive.

Murfman · Mar 2, 2011

Ceramic is much more porous than the live rock we have in our tanks. The "holes" are not the areas that the bacteria colonize, although they are in there. It is the microscopic holes that they colonize. Take for example Siporax ceramic beads; Aquatic Habitats :: Consumables - Miscellaneous - SiporaxÂ® Media, they can host bacteria at a much higher rate than our live rock can. These are great for small tanks with limited space. They don't do anything for the look of the tank though. I have LR that started out as portland cement and oyster shells. It is full of coralline and looks just like any other rock in the tank.

Troylee · Mar 2, 2011

Got cha... I personally keep nothing in my sump except equipment... Rocks tend to collect garbage like I said and makes it a real pita to clean..

my frag system has zero Rock and it thrives...

butts182 · Mar 2, 2011

i have some rock in my sump but only because I have a small amount of rock in the display.

thewackyreefer · Mar 2, 2011

Here's a question that kinda goes along with this topic.

I recently purchased a pillar from The Alternative Reef and do not plan on having any additional rock in my display or sump.

Currently i have about 50 lbs of live rock in my sump since my display is basically a frag setup with no rock up top. Once i add the pillar how long should i wait for it to colonize before i can safely remove the rock from the sump?

mdb_talon · Mar 2, 2011

butts182 said:
I guess i didn't make my question very clear. Since manmade rock doesn't have holes throughout, will it support much less bacteria growth?

Thought your question was pleanty clear, but the answer is the same. It all depends on the material the man made rock is made of. Some materials can be extremely pourous... others less so. Ceramic can be extremely porous for example. Some natural "live rock" can be extremely dense.

Wy Renegade · Mar 2, 2011

My 65gal has almost all man-made rock, made of cement and shells. The rock I have was actually made by GARF, but I've seen lots of people make their own. It holds just as much bacteria, and is full of large holes and openings to provide lots of caves. Here's an old picture;

mdb_talon · Mar 2, 2011

I like the rock, but you need a frag tank

Wy Renegade · Mar 2, 2011

Certainly did then didn't I?! Actually those were mostly frags going into the tank - what I really needed was time to get them affixed to the rock LOL

Electrobes · Mar 2, 2011

This is going to be difficult to write without sounding bias but let's give it a try:

There is definitely man-made rock out there that is more porous than what's available as actual rock. The problem is that people tend to group man-made rock together with what they might have seen from inexperienced hobbyists and/or brand new businesses, or even from what they've seen (Pictures, etc) years ago when man-made rock making had a surge of interest. While man-made rock is still a relatively new market (In terms of retail) these days there are definitely examples of high quality stuff out there.

The best part is that it isn't just man-made rock from businesses like my own, but also ceramic (Alternative Reef) and even epoxy (https://www.reef2reef.com/forums/do-yourself-diy/56978-diy-fake-rock-shelf.html).

The idea that man-made rock supports less bacteria than true ocean rock is like a lot of sayings in this hobby... a myth. You'd be surprised just how porous man-made rock can be. As a test to show potential customers just how porous my rock is, I made an inward concave piece of rock and after it was ready, then poured water into it. The water goes right through it, it doesn't puddle. I can't remember if it was GARF, Pacific East, or some other company but an article was written about how deep the bacteria penetrated the man-made rock. The conclusion was that even with dense man-made rock, bacteria finds a way in.. waaaay into the rock. With porous rock it dang near goes all the way through!

With the way bans on rock have been trending over time, it'll be a matter of time before man-made rock becomes a staple in the industry. Over the years the quality has only gotten better, and companies have discovered many new ways to use it. It comes down to communication, information, and popularity. When one of the three increases, the others will eventually do the same. I believe lately it has been catching on.. I'm usually sold out of stock and after speaking to a couple of man-made rock companies it turns out they too are quick to be out of stock as well (Then again I can't imagine a company wanting to say otherwise!

)

Hope I didn't sound too bias..

butts182 · Mar 2, 2011

no, that's valuable information, and exactly what i was looking for. thanks so much.

BlazinNano · Mar 2, 2011

I make my own rock. It is all ceramic. I have my own kilns and have tried different things with it. I have never had a problem with it. I am in the prizes of completely making my tank all "fake" or man-made rock. I don't consider it man-made because it all comes from the earth just in different textures to start.