So, going back again. After a short period of curing, seeding, and stabilisation, It was deemed appropriate to slowly start adding stock. Now many would be tempted with such a water volume to assume that you can just chuck a load of stock in and try to get the reef looking as established as possible, as 'quickly' as possible. Personally, I'm not a fan of that mentality for a few good reasons.

1. Its a very 'false' impression visually, because you can see that the corals present haven't actually grown 'from', or had a chance to become firmly attached to the substrate  or rock structure.

2. The biological processes of the tank including its critter population, bacterial populations and other fauna, are constantly trying to play catch-up, which can lead to higher levels of background dissolved organics and particulates at a time in the systems life when problem algae and blooms are more likely compared to older more established systems that are able to cope with higher inputs of food and waste etc. This excess of  particulates can also build up in the live rock and substrates too quickly, allowing a much larger proportion to decay and pollute the system, than would otherwise have been the case had the system been allowed to mature at a more natural rate allowing the various secondary micro populations and scavengers to grow 'with' and at the same speed as the growing stock load and waste levels. Gradual clogging is inevitable with all closed systems, that's just an accepted part of long term reef maintenance, but A tank is supposed to clog up over 'years' of use, not start off that way..(think about it.!).

 Admittedly. This slow stocking mentality doesn't apply 'so much' to corals, as they don't load the system up as much with waste products, unlike a fast growing fish load, but even still, corals 'do' need feeding, and do require various compounds that just aren't present in high enough or balanced proportions in a fresh and fairly sterile system.  Balanced levels of available amino acids, nutrients like No3 and Po4 which are in fact essential at lower levels ( despite all our efforts to control them.. ) take time to stabilise and stop fluctuating in new systems, as does the availability of live prey in the form of planktonic larvae generated via the expanding micro fauna populations (an essential and very important consideration with corals such as SPS and LPS) Initially these populations are small and don't fill the system volume up with available and nutritionally balanced food to any significantly useful degree. That comes over time, and with a more established micro fauna population..

 In effect, we are trying to balance a biological see-saw, where we have our corals and fish on one side, and our bio filtration and micro fauna on the other.  Add too many corals or too many fish too quickly, and we tip the balance to the detriment of system stability. the other thing to bare in mind with this see saw, is that the distribution will never be constantly even, because we are adding food at its centre. Initially food introductions will be small and will split (in terms of overall available nutrients) to either end of the see-saw, boosting both our livestock growth, and our biological support crew which is good thing. Over time and with increasing demand from our ever growing populations, our food input will increase, but we always need to remember that balance point between the bio load that our corals and fish place on the system from one side, and the populations and effectiveness of our biological filtration and waste control methods on the other. Get it right and we have a thriving system that maintains very low or near NSW levels of undesirable nutrients. Get it wrong, and we see rises in both free No3, Po4, influxes of problem algae as the system destabilises, Ph issues and ultimately the demise of more sensitive corals etc...Fundamentally, what I'm saying here is, that 'slow stocking' allows you to monitor these shifts in balance more easily, as they will be on a smaller and more controllable scale. This allows you to take 'minor' action should it be required to solve a problem, rather than facing what could potentially be a disastrous collapse of an immature system as the biological capacity caves in under the pressure of a grossly exaggerated load brought about by too much input too quickly.

 In this respect I will offer a word of warning regarding the frequently shouted comment on Bulletin boards " well look, I managed it Ok with my fully stocked system that's only 6 months old "...

What these people very rarely say, is what their nutrient levels are (even if they actually know), they often go on nothing more than the 'appearance' of stock that hasn't had time to show the effects of ongoing and long term stress brought about by instability and gradual malnutrition. So they take it that, 6 months success keeping a coral or group of corals alive 'proves' beyond a shadow of a doubt that fast stocking does indeed work and the experts are all wrong...But I'll ask you to ponder this.. How many of these guys are posting pictures up of the 'same' tank with the 'same' stock several years later ?....The answer is quite simple....Hardly any, and certainly not as many as the more experienced guys who have stocked a tank up over several 'years' because they have learnt by experience and seen the difference in health of a more established and carefully stocked system.... What is commonly the case, is that  fast stocked systems succumb to the abuses they have been subjected to in the early days and the tank very often ends up a conveyer belt for failure after failure as far as coral and fish survivability goes, because the system never gets the chance to build up a reasonably balanced ecosystem that will stand the test of long term function.  Would you buy a new car and then fit a clogged air filter to it ?..

So with that little snippet out the way I'll progress onto some pictures. The following shots show some initial stock that was introduced over the first 6 months, after the initial blooms had taken place, parameters had stabilised and the rockwork had become reasonably active as far as encrusting coralline growth and micro fauna goes..

A Cerianthus anemone, happily extended and catching whatever drifts by in the current, including a regular dose of frozen foods such as mysis, mussel, brine shrimp, and flake. Allot of people worry about these anemones catching fish etc, but in my experience this isn't the case with healthy fish, which will steer well clear. Sick and disorientated fish may be a different case though if they blunder into the powerful stinging tentacles.. And next to him, a Juvenile Maldivian  Arc eye hawkish...Eyeing me up, and waiting to be fed.

With a fast growing micro fauna population expanding across the fake rockwork,  I also deemed it worthwhile after a couple of months to add a few SPS frags to see how they got on.  including a stunning Montipora undata from Simon Clark, and a piece of Montipora capricornis that has a stunning purple growth rim.

Yet further along, and we have a stunning Acropora tenuis growing in front of a thumb gorgonian. (the bright orange coral in the background is a red Montipora digitata). Note both of these corals are right at the bottom of the tank under a 400W halide in 24" of water. Even this deep, they still show good pigmentation at an early stage, which proves that with low enough nutrients and stable conditions, good colouration is still possible even with a more moderate light field and deeper depth. The second shot is of a very small 1.5" Maldivian blue trigger that was added. Now this might seem an odd addition to a reef tank, but in the wild these fish are generally planktonivores catching prey from the open water column. In the six months since this shot was taken, this little guy has grown to about 3" and is as good as gold. He doesn't even bother the cleaner shrimps or other fish. In fact he is a model citizen. Always hanging around his own little bommie near the front of the tank just casually eating what drifts by.

The next two inmates (about 4 months after initial maturation of the system) were an Acanthurus olivaceous, (orange shoulder Tang) and an Acanthurus tennenti (vampire tang). Sadly there was a bit of a story involving the Orange shoulder. You see she was imported as 1 of a very rarely seen 'pair' both of which were very small at about 1" long. These two were caught and shipped together. Unfortunately on the very day I went to pick them up, one of the pair had jumped from its holding tank during the night and had died, so taking pity on the little lost soul that was left, I took her back and added her to the system. Luckily she came on strong and is now a picture of health with the faint shadow of her orange shoulder starting to take shape at around 5" long. The vampire (although only a migrant to the Maldives) was added shortly after as I've always loved these fish with their subtle purple sheen and sleek lines. Sadly when imported these fish wash out colour wise which is why they get ignored. But once settled and fed up, they get their true colouration back which gets stronger and deeper as they grow. One of the reasons I always try to buy small tangs, is that generally, they are far more sociable than their adult relatives so can be mixed with greater success at an early age. Over time, It is possible on occasions, to mix fish that would otherwise cause issues or be a danger to each other if they were added as adults at a later date. The other advantage is that immature fish that have grown 'into' their surroundings are generally healthier individuals over the long run.

In these shots we have a few more corals added. Including a stunning Cynaria (button Coral), a lovely Fungia plate coral which is open all the time. A nice frag of Acropora parallis growing a good base down in the strong surge, and a batch of Seriotopora spaced along a branch in the hope that they will gradually grow and fuse together to form a nice large colony spanning the length of the branch.

Well, as you can see, Things were going quite well. But never let it be said I always get it right.  Shortly after these photos were taken, I started encountering a slight loss of pigmentation in most of the SPS corals and a slight loss of colour in the LPS as well as an overall reduction in growth rate.. so I settled down to some serious testing. At first I couldn't find anything wrong,  with the readings as follows.

No3 0.1ppm, Po4 below 0.03ppm, Ph at 8.4, Ca 440ppm, Mg at 1350ppm, Alkalinity at 8.5DkH Temp stable at 25.5 - 26F and salinity at 1.025.

So scratching my head a bit, I started thinking about light (as you always do) but seeing as my 10K 400w lamps were less than 12 months old and the 4 x 54W T5 actinics were even younger, I doubted this was the issue. so then I started to think about depletion and 'lack' of something. so going on past experience I looked at Iodide deficiency, but after testing realised that this wasn't the issue, not that it ever was likely with the amount of food I feed, algae included which contains iodide, and the fact that with such a large expanse of sand performing good de-nitrification and iodate conversion to available iodide (evident by the low N03 readings) the chances of this were looking slim as  a cause...so I went back to the testing and looked at everything again.

Well to cut a very very long story short, what was actually happening was that I wasn't just below 0.03ppm on the phosphate kit, I was 'drastically' below it, in fact I was at less than 0.005ppm after some major jiggery pokery with a D&D test kit and some different test tubes that could measure a higher resolution. In short this meant that the system was so efficient at nutrient export combined with a recommended volume of phosphate remover, that I realised the corals were actually suffering phosphate deprivation. So with that mystery solved, I halved the dose of phosphate remover temporarily and switched back from the powerphos I had been using, to the old faithful Rowaphos. I then upped the feeding of the system as a whole in an effort to get some phosphate back into the system whilst testing carefully every couple of days to ensure I didn't let it go too far.  Needless to say, in just two weeks there was a marked improvement in the corals, and once levels had risen to a more respectable NSW concentration of around 0.008ppm to 0.01ppm I brought back on line the normally recommended dose of Rowaphos for the volume and everything settled down.

Further information on this situation can be found here, but please note:  This situation is 'rare' and is a result of several combined factors unique to this situation and this system. So please don't go turning your phosphate reactors off, and dumping a load of food in just because your corals are looking a bit faded. chances are in 99% of cases, its 'not' phosphate deprivation. even then, only act on known and confirmed test readings, and take things slowly...never panic and take rash action that may cause even more problems.

http://www.ultimatereef.net/forums/showthread.php?t=225482&highlight=phosphate+deprivation

To date I have had no further issues, and levels remain stable at or near NSW. So with that I'll leave you with a thought. Don't assume the realms of Ultra Low Nutrients are reserved just for the likes of the ULNS and Zeovit systems etc.

With a well 'balanced' and maintained system, with a sensible stock load and feeding regime, there is no reason why these low levels cant be achieved in more traditional set ups, even over the long term. That's not a criticism of these methods (they do actually work and work very well), Its more a 'reminder' that even though there are a multitude of different ways of running a reef tank, The 'method' is only part of the equation. The degree of success 'with' that system, is entirely down to its application and the way 'we' as its users, maintain and treat it.

So with that in mind, I will leave you hanging until the next instalment, when I scare you with tales of an Aiptasia explosion, and Velonia infestation...

See, I told you its not just you guys that get a hard time of it on occasions.

Simon.