Man Made Live Rock
Now before all you know everything's start in on me with the "Never, Ever Use Sunlight to light any tank" nonsense. Let me enlighten you to some facts. I am not trying to convince any new reefer to use it as their primary, nor secondary lighting. First off I have used sunlight with success on several tanks so I really do have some clue what I'm saying here. Now exactly how I do that depends on again the needs of what I'm trying to light. Second, what exactly is so "un-natural" about sunlight? Third, why not?
Those that insist you cannot use sunlight to light a reef tank come up with all sorts of excuses. The main ones I have heard are too much heat, UV overdosing, too much intensity, and "guaranteed" algae problems. There are other reasons but these usually convince most to not even try natural lighting. To sum it up they say "No, you can't do that!!". What I say back to them is "Like Hell I can't... it's my tanks, my livestock, my house, not to mention my life!... So piss off".
So what techniques do I use to allow the use of sunlight you might be thinking. Well for one you must limit the sun's exposure to your tank. You must filter the light with something to minimize unwanted portions of the light spectrum. This is done by applying special films, or other means, to either the window or the back of the tank, possibly both depending on your desired outcome. I also get creative with the use of vertical hanging mini blinds. This, in a sense, mimics the effects of clouds which deals in great part to the non issue of heat. As for the films, I get these generally from either science product distributors and/or glass specialists. It is almost amazing some of the products you can find if you simply look and ask the right people. Granted that some of these films are quite expensive, but remember that they cost nothing more than initial cost to operate and for sure are quite less expensive than the average reef tanks lighting system. I'm not going to go into the details of my research on films any more than this as I want to stay ahead of the pack if ther is such a thing. Actually I just want to feel safe saying what I will about it and until I have the experience to back it up, I'd like to stay tight lipped about it.
Next up is the mother of all excuses, Algae! Let me make this clear. If you take virtually any commonly attainable live rock and you place it in a tank that is lighted by sunlight, however filtered, you will generally get more algae than you can imagine. The catch is that this is a good thing and you can overcome it. In fact you want that algae to grow! You want it to grow to it's hearts content. If you have trouble understanding this, I would suggest that you read up on the causes for the rapid growth of algae.
The number one cause is over abundance of nutrients. They may be Phosphates, Nitrates, Silicates, etc., etc.. Take your pick, the bottom line is that there is too much of it. From die off in the curing stage of live rock to the explosion of microbial processes that result, the whole thing is way out of balance. Run it out of nutrients and *poof*, like magic the algae stop growing so much and so fast. This in great part helps swing the balance back the other way and allows your livestock to take over, which is one of the primary goals of reef keeping. From that point on, you alone are responsible for allowing nutrients into that tank. Just remember that all living things, even bacteria, must eat something or they will die and release their trapped nutrients back into the water causing the cycle to start again. So the trick is, if there is one, is to attempt to rid the rock of excess nutrients without starving the life out of it completely.
Now as for how I do this it goes something like this. Get some live rock, try not to get a bunch of livestock with the rock, or if you do remove it and place it elsewhere until this process is over. Place this live rock in your "seed" tank, preferably leaving enough room to rotate the rocks and remove and replace them with some ease. Now give it a good blast of sunlight. It may take a week or two of fiddling around with your mini blinds to keep your tank from overheating, but keep with it. Use other means of cooling if you need to just don't let it get too hot. You see you are essentially acclimating your live rock to captivity.
The current curing process methods simply are not good enough in my opinion. The rock is still way overloaded with nutrients after being removed from the ocean, placed in a dark box (often wrapped in wet newspaper), shipped for days or longer, then stuffed in a tank that is way different than the environment that it came from. Current practices allow time for the Ammonia, Nitrite, and Nitrate to drop, then stuff it in another or the same tank, then begin loading it up with nutrients. To me this makes no sense, it's backwards. A skimmer simply isn't going to be able to remove pounds worth of dead, decaying, and decayed matter. The pendulum has just swung the other direction that is all. Those nutrients are still in that rock, just waiting for the opportunity to explode out, usually in the form of unexplained algae blooms at a latter date. See some of the current debate, and the facts regarding long established DSB's. How is what happens inside live rock all that different? It is different but the fundamentals are the same as near as I can figure.
Maybe you can load a tank precisely to match the over population of bacterium, nutrients, etc., and keep it stable that way, but I'll bet not. I can't even get close! What happens if you can't get close enough? Then your right back where you started, and an algae bloom of some sort is the common result.
Now that we have that out of the way what we want to do is give your seeds some time to release their nutrient overload in the form of all sorts of nasty algae. The time this takes is completely dependent on the load in the rock itself. It may take you several months to get back to ground zero. It could be done faster, but that is unpredictable by myself. Let the algae grow until it seems to have overtaken the rock then proceed to clean it. Continue this until it stops blooming. Try not to worry about hurting any of the beneficial organisms, they are more resilient than the algae and quite safe inside the rock. The corraline, copepods, bacteria, etc. will survive this ordeal just fine.
In order to clean the rock after it has grown a good sized head of algae you will need two containers, rubbermaid or other suitable sort. Several sizes and stiffness of never used for anything else hand brushes. I use everything from toothbrushes and dish brushes, to toilet brushes. The more the merrier. You will need to get both vessels set with fresh saltwater. One needs to be large enough to hold all the seeds that you plan to use the other needs to be the same size or preferably larger. Maybe two to three times that size. Make sure vessel number two is large enough to splash around a bit, and dilute the nutrients coming off the rock. The first one needs to match the parameters of your seed tank, and have a power head that is strong enough to keep water moving well. The other needs only to match specific gravity, and of course be of good water quality otherwise. The one important difference is that vessel number two needs to be 2-3 degrees colder than tank number one.
Now you take each piece of seed rock and dunk it in tank number two, wait two to three minutes, then scrub as much algae off that rock as you possibly can. Swish it around and place it in vessel number one. The wait is in order for the surface, and near surface organisms, to place themselves deeper inside the rock, which they will do naturally when the temperature swings just a couple of degrees lower rather rapidly.
Continue this until all seeds have been "washed". Now, leave that rock in vessel number one, and break down your seed tank, clean it well, replacing the water with fresh saltwater. Go back to vessel number one, and swish a rock around again, looking for any algae that you missed the first time. Scrub again as needed. Then place it back in the seed tank. Continue this until all rocks have been cycled through this process.
Yes, you guessed it... add more sunlight, wait for the algae to grow again, don't forget to rotate the rocks, then repeat the above as many times as it takes. In the meantime, do not add any forms of nutrients, that includes fish, mobile inverts, etc..
You will know when to stop as there will be minimal algae left to clean. This should take at least one month for cured live rock. If you do not get serious algae blooms you either have exceptionally clean live rock, possibly dead entirely, or you need to add more sunlight. The other thing that you need to be doing during this phase is eliminating any pests that you notice on your live rock. Aiptasia, gorilla crabs, etc..
I must admit however that I have seen cases where not all rock subjected to the above becomes infested with algae. These are however few and far between.
At this point you can allow your seed tank to mature and start adding your livestock provided you are sure it has stopped producing mass quantities of algae. This rock is now automatically acclimated to whatever lighting you want to use. Stepping down in light has never caused any issues for me. To me any artificial light is a step down compared to sunlight. Add mobile animals last and do not go too fast adding other items!
To understand why this works think of two sponges. One is the rock the other is the algae. When the live rock is removed from the ocean, packaged, shipped, and "cured" it sucks up all the dead material it can, this is usually quite a lot. When you get it to your tank and attempt to get it controlled, it just waits there for the correct environment then it starts pumping all those accumulated wastes back out. Usually in the form of algae. Sometimes it happens right away. This same thing can happen over time as the rock reaches saturation of nutrients. This can happen for many reasons. Neglect, poor equipment, rapid change of bio loading, overfeeding the tank, as well as other causes.
To put this another way. I understand the dynamics of live rock and denitrification and that the end result is supposedly a zero, or near zero, net gain in total system nutrients. That is the way it is supposed to work. If what I'm saying is untrue then why is it that you can take any freshly cured live rock, place it in perfect specification salt water, add sun and get more algae (read nutrients) out of it than can sometimes be believable?
My point is that I do not feel that in practice the denitrification properties of live rock, DSB, good tank maintenance, nor all combined are sufficient enough to remove nutrients from the average reef tank that has loads of hidden nutrients from the start. It takes more than that. There need to be other methods employed to remove excess nutrients. While good over all tank husbandry is a good thing, I think starting of with "clean" live rock helps keep things in balance longer.
The process above explains how to force the algae to act as an opposing sponge to suck out all that excess material, prior to using it as a showpiece, so it cannot hibernate inside the rock only to wake up at a latter time and cause an algae explosion. This same process can be used to "treat" established live rock that is having trouble. However, care for whatever external organisms you have must be taken into account. Please note that live rock seems to be able to seek nutrient equilibrium with the rock surrounding it, so it may be possible to clean just those that have no attached life forms in this way. I believe that the time needed to do this could wear on even the most patient though as the effect is noted to be much slower from rock to rock than from rock to algae.
I also like to equate the whole thing to being incredibly similar to using a plunger on a stopped up toilet drain. Where the toilet is the rock, and the plunger is the algae.
If memory serves, I believe Eng lived very near a source of live rock, which without the issues of transport trauma to the rock, he was very successful at creating a balanced reef system. I have seen documents on many reef tanks of those who live near a source of live rock that they attained themselves. These tanks generally look a lot nicer than those of people who have used live rock that has been shipped. The Germans were able to capitalize on Eng's approach in part due to the idea of extreme limitation of nutrient import into the tank. My opinion is that you need both natural and technical methods acting together in order to produce the reef tanks of tomorrow.