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Natural live rock VS Artificial live rock

I have been confronted with this question multiple times over the last few months. This is mainly due to 2 reasons.

1. Reefers want to make sure they do the ethical thing and not destroy nature by removing natural live rock from the reef.
2. BUT more importantly reefers are exposed to a variety of newly available artificial live rock and the perceived“price reduction”, when compared with natural live rock.

The 1st concern should be a deciding factor for everyone as our impact on nature should be limited as far as possible. I always thought that any alternative to natural live rock is the best option because of the propaganda around the destruction of nature and natural reefs due to the removal of natural live rock. Then I met people involved with the mining of calcium and other products we need to manufacture artificial rock and were shocked. Google the effect of mining on nature and even reefs and you will realise that far more damage are done by these mining efforts (sediment alone are one factor that have a major effect) to supply us with basic elements for good quality artificial live rock than the actual removal of SUSTAINABLE natural live rock from our oceans.

So I have to say, till we can say with certainty that the raw products we use to manufacture our artificial live rock, did not come from destructive mining operations that artificial live rock cannot be said to be less destructive than natural live rock.

Now to the second part. Here you must understand I am looking purely from an aquarium perspective and the impact these different live rocks have on the fish, corals, inverts and biology of the aquarium, then lastly our visual perspective. Then I need to state that my comments are not applicable on ULNS (Ultra Low Nutrient System) or a biotope such as a sea grass and sand bed system that already has sufficient habitable bacterial surface area.

Why do we use / need natural live rock? Natural Live rock in my personal opinion is used for the habitat it creates for both micro and macro organisms and the organisms it bring to our closed “mini” marine environment. Healthy natural live rock is the MOST IMPORTANT BACK BONE OF A HEALTHY MARINE AQUARIUM. This is because the oceans are very stable and stock really low, when compared to our over stocked and unstable marine aquariums. Healthy natural live rock will give you one constant in this environment and that is loads of places for bacteria and micro living organisms to natural live and thrive in. Different strains of bacteria are the most important organisms a good aquarium keeper must manage. The micro-organisms end up eating small particles of food and other protein based particles and then through their reproduction, they end up feeding the visible organisms like fish, corals and invertebrates.

Why don’t we like natural live rock? My only concern with natural live rock is the pesky hitch hikers that sometime come with natural live rock. This is also the main reason some of my customers decide to use artificial live rock, they do not want to stand the chance of getting these hitch hikers into their aquariums. The solution to this is easy but a bit time consuming. Do not add new natural live rock directly into your aquarium. Place them in a quarantine system and use food and visual inspections to find and remove these hitch hikers.

What are the benefits of artificial live rock? The way some of these are manufactured today they look like natural live rock but they do not have the hitch hikers we do not like to have in our marine aquariums. Natural live rock tends to cloud the water initially but this clear up after a few days. Due to the way most of the artificial live rock is manufactured, most artificial live rock does not cloud the water.

What is the drawback of artificial  rock? So if artificial rock has all these benefits, why not recommend it? Well the main points that are concerns to me are:

  • Some of the artificial rock available are hollow and will float till it fills up with water, but this is a disaster waiting to happen. Due to the nature of salt water that rots when stagnant, when this water is rotten and start to leach back into your main system it systematically destroys your carefully planned marine aquarium environment.
  • Other artificial rock are made of materials or constructed in such a way that are not conductive to the growth of a healthy bacterial and micro-organism populations. This means that they are not porous enough for these organisms to thrive in.
  • Then there are the DIY cement based artificial rock. This type of artificial rock has a few major drawbacks. Firstly they cannot be manufactured with enough places for a healthy bacterial and micro-organism population. Secondly and this is a very important point, the weight is vastly more than any other type of artificial rock and therefore extra precautions need to be taken when building your stand AND aquarium bottom. Thirdly is the curing process, if you do not do it correctly and for long enough the leaching of salt, curing agents and other impurities in the cement can and will destroy the livestock under your care in your marine aquarium. Lastly (and this is the one that are difficult to proof but MANY YEARS of experience proofed it to me) the long term leaching of undesirable chemicals from known and unknown impurities can have serious repercussions, and not only to any corals or fish that we add. They can also hold back the development of bacteria and micro-organisms populations, which as stated earlier are VERY important for a healthy marine aquarium environment.Testing for these impurities are extremely difficult as normal test kits will not pick them up, you would need a labs analysis AND someone to interpret the results. Then you still have the problem of finding a solution. One of the first and most annoying problems reefers experience are nuisance algae growth.
  • Currently there are a constant flow of new types of artificial rock being introduced to the market and I do not want to include them into the points above as some of their claims are impressive and need to be investigated more before a decision can be made on the possibility that they are a good alternative to natural live rock. But that is different kettle of fish.

Now back to a term I used in the introduction, namely “Perceived price reduction”. I make this bold statement due to the fact the user of artificial live rock does not take the future costs into consideration. The future costs are not limited to the clear cut costs but also hidden and unforeseen costs.
Clear cut costs include items like additional water changes, micro foods, filtration, bacteria and possible losses due to insufficient buffering capability.
The hidden costs include, but are not limited to, the use of extra additives, other chemicals (to fight of problems caused by either the lack of natural live rock or the presence of the artificial live rock) and effort by the hobbyist to keep the aquarium up to a healthy standard.
Unforeseen costs are exactly that. I found extra costs include things like additional water changes, livestock losses and/or mysterious symptoms or diseases.
Therefore the costs of using artificial live rock can be much more than just the amount you paid for it up front.

My conclusion is therefore that natural live rock still trumps artificial live rock, as the only big drawback of natural live rock is the hitchhikers and they can easily be dealt with. But I keep my options open as I am sure a new product will come along in the future that can negate most of the major problems associated with artificial live rock.