Reply to a thread stating that a user felt that a change to a different brand of salt resulted directly in a Cyano bloom within their aquarium.
Although this thread has in places taken what can only be considerd a political/personal turn, im going to stick to the promise i made earlyer and try to offer some objective opinion on the subject of Cyanobacteria, water changes and even tank crashes. so if you think im gonna get involved with all the customer / supplyer stuff, sadly.... your in for a very boring read..
To touch base and save me going over some old ground, heres a copy of what i said on the salt poll thread..and afterwards Ill try to ellaborate on a few points of special interest.
I'd agree with this statement in 99.9% of cases. The rest are simply either pollution, or general poor husbandry with regards to system wide nutrient loads..
Again...This has been the case in the vast majority of situations I have looked into, and Ive done it myself a few times over the years..No biggy. just something you learn by experience and investigation..
fwiw: I voted that I currently have Cyanobacteria using a different brand.
The reason why ive voted this way is quite simple. Up untill I stripped the main tank down recently for a rebuild (the sump tower and 4 tanks are still running) the tank had run predominantly on Instant Ocean. and you know what...I still and allways have had cyanobacteria growing in there, usually a bit across the tops of baffles, and a bit on the surface of my chaetomorphyllia bed..(as alot of people do)...the rest of the tank was pristine.
The truth of it is that Cyano exists in all systems in one location or another, and in varying size populations...It may be a large matt across cirtain surfaces that are prone to high levels of DOC (across wiers where it feeds from the high nutrient miniscus layer) or it can just sit at very small levels in more stagnant areas like floating algae beds where it feeds off surface scum where high levels of coral mucus have collected. But make no bones about it...If you have a tank, you have a population of Cyano bacteria present...somwhere.
The problems start when you change the chemistry of the system to any significant degree (and im not just talking Ca/Alk/Mg etc) there are a whole host of other elements in salt that can affect the closed environment as a whole if you suddenly alter them...and alot of them you simply cant test for with hobbyist kits.
The same applies to inconsistant top up causing wavering salinity, poor temperature control, even having all your windows closed in the house at the onset of winter causing changes to ambiant pH levels from what the tank may have had over the summer months etc etc...All of these and more can trigger off a Cyanobacteria outbreak, becouse you fundamentally shift or temporarily interupt major dissolution and precipitation process within your LR and substrates that rely on chemistry stability to function at a constant rate in comparison to other processes within the system.
For Cyanobacteria, a substrate or porous medium such as LR that has had diffusion interupted or imbalanced for any reason is like a fully laid out dinner table just waiting for someone to sit down and take advantage...Remember the Cyano is there already..its usually just at such low levels under stable conditions that you just dont notice it so much, but as soon as you lay that table by way of disrupting stable diffusion etc, you can bet your bottom dollar that it will dive in and take advantage, only dissapearing again after it has run out of food...And this is where the rub is..
If your already testing and showing extremely low nutrient levels in the main water column, all you do by doing even more water changes than you need, is upset that balanced system even more, becouse you keep shifting the perameters again...The more you change it (bigger water changes) the more you introduce water above the substrate layers and LR that is of a completely differing chemistry to that held within these regions...Then the laws of physics and chemistry kick in to balance out those differences...whats gone in, must come out and visa versa untill both are the same or as near as the two environments will allow. Once things have balanced out again and stability has returned, is usually where you start to see a die off of cyanobacteria as its uptake ability outsrips the now lower supply...
In essence im saying much as David said....
Cyano blooms are not directly attributed to the salt or a particular brand, (unless its a batch issue where the chemistry is seriously skew, which if you feel that's the case you should send a sample with a polite letter to the supplyer to test...lets be honest...every manufacturer has an occasional batch issue in any industry...)...Its more linked to changes 'we' instigate in the system, that upset any stable regime we have had up untill that point in time...
Ok so to go one step further.
Earlyer I asked people to offer histories of what they did on the system prior to it developing Cyanobacteria blooms...lets be clear here though, the Cyano was allready there, as it is in just about every system be that new, old, begginer, or proffesional...It was just encoraged by a given triggering factor to spread to other locations becouse there was a new source of available nutrient.
what needs clarrifying (and is probably impossible to determin without lab equipment in some cases) is 'where' that nutrient is coming from...We can test the main water column and we can test the source water which rules out 2 routes, so the first thing we have to deffine is the 'route' the nutrient has taken...
If Cyano suddenly starts to appear shortly after we have changed salts and ruling out any major changes to top up quality, or any other chemicals added etc, then our most logical course of action is to test both points in the chain...If our water change water tests zero for No3 and Po4 then we can rule out that as a 'source' even though it may still be a 'trigger' (its important to distinguish between the two)...Likewise with our main tank water...If we have nutrient levels at or below average levels that are widely accepted as being less condusive to problem algae growth (sub 0.03ppm Po4 and sub 5ppm N03) then we can rule out a water column fed issue.
Take away those two factors and we are left with two remaining 'source' points...1: food that we add that may be dumping in quantities of nutrients at a level that encorages the issue whilst being soaked up quickly enough to give a low reading in our main water tests..(commonly the case in systems with a high degree of hair algae growth) or 2: Our substrates and LR are releasing nutrients up and outwards as a slow release mechanism whereby algae moves in to take advantage on its surfaces, taking up the nutrients at the same rate they are released, giving rise to still low free nutrient test results. (remember tests only show you whats going on in the middle of your aquarium...they dont show you whats going on in the murky corners, under and in your live rock or within any substrates you have.
So, once we have narrowd down the 'source or pathway' of nutrient, we can then look at what 'triggerd' that release...(lets rule out food here seeing as its so easy to diagnose by omission or switching over a period of time)..
So lets assume..that after ruling out all other variables that are known to 'trigger' such releases from substrates...ie...sudden or inconsistant changes to salinity, sudden or inconsistant changes in temperature and sudden changes or suppressed pH..we have narrowd our focus down to the salt we have just switched to as the 'trigger'
The first thing we have to consider when looking at salts is that we as hobbyists only have a certain capacity to test the content of any salt...with around 100 elements included that make up a formular, we only have the capacity to test maybe 10, and of those only 4 or 5 to any degree of reliable accuracy with average hobby test kits...this basically means that we only 'know' 10% of the picture at any one time with any brand of salt...thats unless you actually pay attention to the tables printed on the side and spec sheets that come with many salts...
As hobbyists we commonly only talk or recognise significant changes in the main core elements...we chop and change to get better Ca, better Mg or better Alk etc etc...what we very rarely do is compare differences in levels of lesser elements such as chromium, manganese, molybdenum, bromide, boron, etc etc etc...the list just goes on and on. what makes it worse is we simply in many many cases just dont know what affects these elements have on the organisms in our tanks from bacteria to fish, we know even less about what happens when we change the levels of these elements....and not all salts have all the same elements, becouse thier researchers may be subject to differing research material which disctates what they do and dont add to the mix in whatever quantities...In many cases they are there just becouse they are found in nature so logic dictates that we include them in a mix becouse something is probably reliant on it but we dont know to what degree.
The point here is to realise that when we change salts, we are not just changing a few levels. we can in some cases be drastically changing a vast array of elemental levels, raising some up that may have been low previously, dropping some down that may have been elevated. so logic dictates that somwhere along the line we will fundamentally shift not only the biology going on within a closed system, but also the hodgpotch of chemical reactions that go on in the background under varying conditions from system wide to micro habitats where other factors may affect things further, such as low pH areas under and within substrates etc..Remember tanks arnt just a single habitat...they are a multitude of differing habitats with differing conditions that go to make up a whole functioning unit..just like a reef, but on a macro scale...maybe not as diverse, but still very very complex in how all those factors come together to form a stable habitable unit or overal environment.
So it begs the question..
If we are going to change something as fundamental as our salt which contains a huge array of possible causal factors when it comes to not only chemical stability within the system but also biological factors that can shift the fundamental function of things as diverse as bacterial action, population, to things like coral pigmentation limitation or encoragement, then we have to accept that in any changes we make there is a certain amount of 'risk' involved with that change...thats just basic logic...no science needed there..
Marine organisms are incredibly adaptable in most cases (thats the reason we have the success that we do in keeping them) becouse make no bones about it, the chemical soup we subject them to is in most cases about as far away from natural as you can get when you factor in the oceans vast capacity for dilution and stabalisation at a chemical level. Yes there are factors that determin shifts in overal balances within the ocean be that depth, bioload or local influances, but by and large even those differences are pretty stable to that area on an ongoing basis even if they are not in keeping with the whole..and this is where our tanks come in..
When we use a certain brand of salt for any extended period of time, we are creating a local environment of specific perameters that our organisms have to and will in most cases adapt to..what we do when we switch salts is tantamount to taking a montipora from a reef in the maldives and dumping it in the water off the coast of sharm el sheik..Is it any wonder that in some cases that change is just simply too much for that coral to handle? Its still salt water, the temperature may be same and the main core elements may be the same, but look deeper and we may see differences that we just smply werent aware of, nor how they would affect that animal at a biological level...when we switch salts... we arnt just doing this with a single coral, we are moveing our 'entire reef' and everything that lives in it from fish down to bacteria and subjecting them to drastic changes in the environment that they then have to adapt to..
So..putting it very simply...If your going to change salts...dont just think about what your gaining in terms of an extra 50ppm Ca or such, there is a whole host of other stuff that you are shifting as well...some shifts may be better, some may be worse..but in all cases you have to give your system and its inhabitants the most gentle transition possible to allow them to adapt with as little fuss over as longer period as feasibly possible..
In most cases i'd say that if you are going to switch brands (regardless of which brand it is) then start it by splitting your existing changes into two..if you do 20% per month, split it to 1 x 15% change with your existing salt and a 5% change using your new salt for the next couple of months...then up it to 10/10 for another two months, then 15/5 in the new salts favour, finally settling back to 20% with your new salt after 6-8 months...Do them as seperate changes and dont mix in the same bucket as you may get adverse chemical reactions between the two brands when mixed from dry in the same solution..
do that and your minimising the stress on the system, its biological function and its chemical stability...(as the old saying goes...nothing good happens fast in reefkeeping)
So lets finish with cascade failure as it seems a relevant subject in the context of this thread..
Cascade failure happens when something triggers a detrimental downturn or rapid acceleration in the biological function of the closed system, and that change is faster than the systems ability to stabilize itself...this can and usually is both a biological and chemical process..
It usually starts with one of two routes..either severe chemical imbalance which triggers off secondary biological collapse (kalkwasser overdosing a case in point....1st you get a rapid rise in pH, then you get massive ammonia pollution as the bio load starts dieing off..the more that dies the more pollution rises killing more and more robust species as it goes until finally the system collapses completely resulting in the loss of all bio-activity bar bacteria.. The other route is biological collapse..where just one major organism dies resulting in large increases in pollution and a resultant rapid growth in bacterial function which takes up available 02, lowers the pH causing further die off and yet more pollution..there are several intermediate steps but pretty much its usually the same results
Thats basically cascade failure in a nutshell.
Now, the interesting thing is that no two systems are alike and its only time with a system and how it copes with the many variables that tells us how robust that system is in respect to how it handles all the changes that we throw at it on a daily and ongoing basis...some systems are simply far more sensitive to changes than others...there are various reasons for this, but by and large its a given...no one can say that the same changes in one system wont affect another system to a much greater degree, even if those changes are done at an identical level..
in essence I'm saying....if you up your Mg level by 25ppm in one system without any significant changes visible in the corals etc, thats no guarantee whatsoever that the same 25ppm increase will have the same affect in another system even if they both started out at the same levels...there are just way too many variables to take account of..chances are that the results will be similar, but its never 100% the same result across a hundred tanks and a few thousand corals...thats just reef keeping I'm afraid..
Taking into account all of the info above...It is not in my opinion unreasonable to consider the fact that in the rare event of a system collapsing through cascade failure shortly after switching salts, that that 'particular' system, was more sensitive to changes across a broad range of parameters than the vast majority of other systems...It may well also be the case that once the situation started, then further changes (water changes etc) in an effort to remedy the situation simply triggered an even greater collapse of the systems stability.. even going back on yourself can upset things further once a system has started to slide and Ive seen some very very experienced reef keepers go through this so its not a newbie thing, nor an easy thing to stop once started..
Unless you know for a fact its a definite pollutant which does need removing, Sometimes its actually better to just 'stop' fighting the situation by making more and more water changes, and make the decision whether to let the system stabilize where it is whilst removing stock that is in danger or showing signs of collapse which will add to the problems...in effect, what you try and do is create a fire break in the chain of collapse before moving forward. what adapts will adapt, what cant is removed until it can be re-acclimatised under more stable conditions later..
water changes are great at diluting a problem, but they wont solve system instability if your adding further changes by way of a different salt mix...all that does is 'add' to the problem..thats not an issue with the salt...its an issue with understanding what you are playing with in the first place.
So I'll close here on a final note..
after all is said and done...Its very 'easy' to point a finger in one direction when it goes wrong...Its even easier when we have a problem on a previously trouble free system and there is only one obvious change we have made..."Its gone wrong, this is the only thing that could have caused it so it must be so"...when the truth of the matter is that it may well be 'and we have to logically accept this fact' that its not so much 'what' we have changed, but 'how' we changed it..
As hobbyists we have limited ability to point the finger at a given cause with any certainty when dealing with such a complex amalgamation of chemistry and biology that is a reef tank....We would like to believe that we are never in the wrong and its down to anything other than ourselves when it goes tits up....The truth of the matter is...We are all playing with chemistry sets (usually blind folded) and we trust manufacturers to get it right so we can have faith and proceed with as little fuss as possible....But manufacturers can only do so much...They can only do the best they can with a product and offer the best 'advice' they can when using that product....what happens after that fact is 50% down to how 'we' instigate its use, and 50% down to how our systems handle those changes..
Part of running a reef tank is accepting that there are no certainties...there are no deffinates and there will always be situations that just defy any concrete conclusions, rhyme or reason, regardless of how it at first may appear..
Unless you have a definite and quantifiable path of cause and effect that has no possibility of alternate source or taint, then you cannot in all honestly point the finger in any one direction...
When we dabble with changing things, we have to accept that there is always a certain amount of risk...The degree of risk is proportional to our understanding of what we are doing, and the rate at which we make those changes..
I hope in some small way this has offered an alternate viewpoint on the subject without pointing any accusing fingers...that doesn't help anybody at all. If people want to find out 'what' went wrong, then they have to start looking at whats going on 'inside' the tank not who put it in there..once you work out one...you usually find the answer to the other..
PS: excuse any spelling errors etc...I really couldn't be bothered to go back through that lot again after typing it all out...you'll just have to live with it.