Reef Discussion

[MavG]

I asked this question in another persons post and there didn't seem to be a conclusive answer.

so i ask this question, Not taking into account the major elements, (alkalinity, calcium, magnesium, potassium) what frequency of water changes, % size and times per cycle (week month) are needed to replce the trace and minor elements (responsible for colour etc) are needed to replace these elements.

the reason i ask this question is:

every time someone asks about using a trace/minor element supplement, its the same answer, "frequent water changes should be all you should need to replace trace elements", AGAIN i am not referring to the major elements, we all know regular water changes replenish these to a certain extenet.

Now, im not saying that water changes dont replenish ALL elements, includeing trace elements to some extent, nor am i trying to induce an argument.

All im asking is, where is the research showing that regular waster changes are ALL thast is needed for supplementation in a mriane aquarium, in particular trace elements, and where in that research is there a correlation between, tank size, stocking density, frequency of water changes and the size of said water changes in order to replace these trace elements?

Indeed, water changes do lesson the amount of supplements needed to be supplemented, and in some tanks, may be all that is needed, however, such a broad statement that i hear all the time, such as regular water changes are all that is needed to replace "trace elements (again forgetting about major elements) is in my opinion preposterous.

trace elements oxidize and are used up every quickly, especially in heavily stocked aquariums, so supplementation of trace elements is not only, i think beneficial, but nessecary, in heavily stocked aquarium, even moderately stocked aquariums, as is supplementation of major elements.

BUT, if someone can show me the research or documented evidence to back up the hypothesis that regular water changes are enough to replace minor and trace elements, then ill take it on board.

Another thing i am interested to hear is WHY people will not add soemthing they cannot test for, is this some stigma that comes from consumers being sick of manufacturers trying to jam another "snake oil" product down their throat, or is there a reason behind this?

As i see it, trace elements, especially in heavily stocked marine aquariums need to be supplemented,, hell, you cant test for ALL the minor and trace elements in Artificial salt mixes, BUT, a lot of people use artificial salt mixes, if trace elements were not needed, why would they include them in artifical salt mixes? otherwise im sure everyone would just be using Sodium chloride, calcium chloride, sodium bicarbonate, magnesium sulphate and potassium chloride and supplementing nothing else.

but, again, show me some hard evidence and research showing the information stating that water changes are all that is needed to replace trace elements and ill take it on board.

lets start a constructive conversation so we can all learn something.

 

[mscott]

I had the answer to this just yesterday now I've forgotten. grrrr

 

[MagicJ]

As a starting point

Another thing i am interested to hear is WHY people will not add something they cannot test for, is this some stigma that comes from consumers being sick of manufacturers trying to jam another "snake oil" product down their throat, or is there a reason behind this?

My main reasoning for this is that there may already be sufficient levels of the particular element and that adding more may actually cause more problems than it fixes.

If your alkalinity is sitting at 15 you don't want to be adding any more bicarbonate as this will have serious consequences for your corals. Now, this is an extreme example but it does serve to illustrate my point.

Minor elements are basically impossible for the average hobbyist to measure so how do we know where their levels stand? And can adding more when they are already at acceptable levels do more harm than good. Unfortunately, I don't know the answer to this question.

Interesting question - hopefully we will get some answers.

 

[MavG]

I see average hobbyiest in your post. I agree that it is hard to determine for someone without experience weather or not to add trace elements, but this is why manufacturuers use a dose rate per week. and good manufacturers will work out the correlation between these elements and other trace you can test for and base an advanced dose rate on this.

I think this can go both ways, yes a lightly stocked tank, you could get away with it, but in a heavily stocked tank, they can (and most usually are) very heavily depleted, and thus need supplementing.

if you look at the red sea reef care range, each of the trace bottles has several ions in it, but only one that can be measured by their colormetric test kit. I assume (and i am only speculating here) that there is a correlation between uptake of this ion being tested for, and the addition (and depletion rate thereof) of the the rest of the ions in the mix contributing to colour.

In simple terms, manufacturers put dose rates on their trace bottle to avpoid overdose, and most elements deplete and are oxidized quickly. the dose on the bottle, in a heavily stocked tank, may need to be doubled and this is weher observation of the reef enthusiast will tell them if they are adding too much or not enough.

then manufacturers can go the step further and work out a correlation between elements based upon uptake by corals and depletion as well as ionic balance in seawater and base a test kit testing for something that is able to be measured.

 

[192k]

The question you ask about how many water changes are needed will have an entirely different answer for every single system. There is no one answer that can be given.

Salt manufacturers add minor and major trace elements in ASW because they are making a mix to mimic natural salt water.
There are around 70 major and minor elements. There is no golden number that will tell you how many water changes and what percentage of them will replenish a system. It's a matter of testing and supplementing, if required.

Dosing rates are always given as a base indicator.

Everything should be tested that is dosed, to monitor levels. Add too much iodine and you will wipe out your whole tank. More is not always better in this regard.

 

[MavG]

I agree with everything that you have said, and all are things i covered in my original post.

What i am looking for however, is why are water changes recommended to replenish trace elements when as we have said, every system is different?

Im looking for some actual figures to support regular water changes for replenishing trace elements over supplementing, as i dont think there is any and the advice of "do regular water changes, that is all that you need" is not a sound piece of advice to be giving out.

Read through my posts, i go over dosing, manufacturers trace elements supplements and testing for them, and the theory behind my thought process.

Again, i will say, this is an attempt to get to the bottom of this, and start a constructive conversation.

 

[brendore]

Good question G, time to dust of the ol thinking cap and see what we can come up with

 

[MagicJ]

I spent about an hour last night on Google trying to track down some research - I got a couple of reasonable hits but need to do some more reading.......

I suspect that there will not be a 'right' answer MavG but definitely a worthwhile question.

I would be interested to know what effect reduced levels of trace elements has on our inhabitants??

 

[NiCd]

There is a lot more to it than the scope of your question covers entails so we can either widen it or have a half discussion .

Your depletion is relatively easy to work out and the short answer is that only 100% wc will get the level up to that of NSW

The second thing is what are the levels of these elements actually required by corals and does lower or higher than NSW affect corals.

Red sea seem to believe through their studies that having higher levels than that found in NSW induces better coloration but there is also equal studies that have shown that corals adapt to either lower or higher levels of trace elements.

The levels RS recommends if induced straight away would cause serious issues to most corals but if introduced correctly over an extended period of time have been shown to increase coloration in most commonly kept corals.

There has been reports of these levels causing alot of issues in more delicate species though

There is a very fine line between in this area of excellent colouration and causing various tissue damage, this is why its only recommended for advanced users.

One the other side of things it has been shown that most corals can adapt to having levels far lower than NSW, it does come as some consequence but it is considered fairly minimal compared to things like phosphate levels over 0.06

Lower levels of things like iodine is considered risky however as these are used by the corals to aid their immune system and as not things that can be stored by the corals.

 

[NiCd]

Sorry looks like there has been a few posts in the mean time, have been typing this out over a long period whilst watching TV

The usage levels stated by red sea were come at by breaking down 30 commonly kept corals to their elemental composition and studying the ratio which was present, averaging this out to come up with a rough usage ratio across the board. The issue with this is that if you have a reef dominated by a particular coral then it will not use it in the same ratio

It also fails to take into account that corals cannot store particular elements despite them being required by corals

Interestingly they also found that when there was a high level of trace eliments that the corals growth was inhibited that is why they separated the growth program for the coloration program and recommend that they not be done at the same time

 

[brendore]

I think (and this is my opinion so don't shoot me if I'm wrong) that it stems from the old days of reefers where many used NSW to do water changes. System were basic, with basic aquascapes and few calcifying organisms were housed. It probably started out with someone saying "I use NSW for my water changes and my corallimorphs have never looked so good!" and applying the 'typical' water change ritual of 20% a week/month or whatever, it has steam rolled since than that X % water change per Y amount of time = good water chemistry and therefore happy organisms.

As our understanding of water chemistry and elemental uptake have increased, this 'rule' gets chopped and changed with the % and time the only things being changed, instead of applying the knowledge we already know to get an understanding of what the uptake of the elements are for the organisms being housed, volume of the system etc. to be able to either dose the correct amount of T&M elements or perform enough water changes to make these corrections. Instead manufactures have taken what we know about marine chemistry and applied the relative factors of elements into salt.

I think the reason why there is no supporting documentation is that this water change 'rule' has become so engrained into the hobby it's perceived as being truthful, therefore as perceived as being truthful no one has bothered to perform the studies in enough depth and with a large enough sample to make a definitive 'rule' that say for instance you have a 200L system, you need to be changing 37% of the volume per month if you have X population of calcifying organisms within your system.

I agree with MagicJ that I doubt you will ever find a definitive answer to that particular question, as every system is different, housing a huge variety of organisms, in differeing stocking densities, with different filtration methods and differing water quality. There are just too many variables to gain such an answer.

However, I think that it is up to the hobbyist to educate themselves with a bit of knowledge about the organisms they are keeping and their elemental uptake (which can be painstakingly difficult I know) and dose or perform more regular water changes to supplement the T&M elements being taken up by their stock and being lost through means such as skimming.

It would be great to see a document containing even modestly basic uptake amounts for certain coral and invertebrate families, with the results of such a report being able to be used by the hobbyist to calculate relatively accurately how much T&M elements they'd need to dose, or the amount of water changes needed to replenish the T&M elements.

 

[NiCd]

If your interested Brendan I would suggest speaking with Paul Besant he is one of the marine biologists that worked of the 2 year study done by Red sea. I will pm you his email address Im sure he wouldnt mind chating or sending you some of the information

 

[192k]

I think a valid point about water changes should be raised.

The two main reasons for water changes are:

I think in order of importance
1) Nutrient export

And

2) To replenish trace elements.

This is the advice I was given when I started and I'm sure many were before me.

How many water changes and what percent are needed to replenish trace elements? Enough to being them back to NSW levels.

I am sure that all 70 or so elements could be tested for with the correct equipment and you would get a more quantifiable result.

 

[MagicJ]

But, if these trace elements are essential to the welling of our inhabitants, water changes will never replenish them.

Lets assume that NSW contains 5% of element A. Over a period of time the corals/skimming etc reduce this to 3% - a 50% water change will only increase the amount in the tank back up to 4%. And, over time, this will gradually reduce to 2.5% with smaller water changes reducing this figure even lower. In reality, the water changes would have to be greater than 50% to increase the concentration and only a water change of 100% will increase the level back up to 5% again. (I think I have the maths correct ;))

What I haven't taken into account is the rate of depletion and what concentration level do the corals actually need - if NSW has a concentration of 5% but the corals only require 2% to be happy than water changes may suffice.

 

[VaultBoy]

I like the way you put that MagicJ I have never realised how they could deplete like that... It made me think.

Even with large water changes all traces and minerals would slowly approach zero... That is clearly not the case so where is it coming from to make up for whats being taken out?

It has to be in something we put in our tanks... It has to be food!

How much of these traces and minerals are present, and at what levels, in the food we put in our tanks?

And the question has to be asked.... Do we really need to do our weekly water changes? Or are we capable of maintaining water at a suitable level with todays technology in filtration and reactor systems?

 

[MTG]

And the question has to be asked.... Do we really need to do our weekly water changes? Or are we capable of maintaining water at a suitable level with today's technology in filtration and reactor systems?

Was waiting for someone to say this. if your phosphates and nitrates are showing 0 shouldnt we not have to do water changes if we add the required trace elements? That is a question i would like someone more known to chemistry to answer for me!

 

[brendore]

If your interested Brendan I would suggest speaking with Paul Besant he is one of the marine biologists that worked of the 2 year study done by Red sea. I will pm you his email address Im sure he wouldnt mind chating or sending you some of the information

Cheers Adam. I'll see what answers he can give

 

[MagicJ]

Even with large water changes all traces and minerals would slowly approach zero...

Not quite correct - the concentration will, at a minimum, approach a figure based on :

Concentration of the element in NSW x Water Change percentage

e.g. if the element represents 5% of NSW and we change 20% then the concentration in a tank will gradually approach 5% x 20% = 1%. It will only approach zero if no water changes are undertaken.

That is clearly not the case so where is it coming from to make up for whats being taken out?

I am not sure that this is correct - how do we know what the level of some of these minor elements actually is? Few, if any, would have the capacity to accurately measure for the majority of these elements. Maybe they are being slowly depleted but the corals are able to adapt and survive - maybe this is the cause of some coral diseases :confused:

 

[NiCd]

Thanks for fraising that better Magic I tried to get that point across with the only 100% water changes can get the level up to that of NSW but really didn't phrase or explain why that is.

We know the average use of calcium for various types of reef tanks, we also have the usage rate of different "major" trace eliments in ratio to caclium usage (averaged across 30 commonly kept corals) thanks to the red sea studys. If there is interest (because it will take a bit of number crunching, coffees and swearing to get it done) we can show the level of delesion over periods of time using the most common 5%/week, 10%/week and 20%/month water changes?

 

[MTG]

Thanks for fraising that better Magic I tried to get that point across with the only 100% water changes can get the level up to that of NSW but really didn't phrase or explain why that is.

We know the average use of calcium for various types of reef tanks, we also have the usage rate of different "major" trace eliments in ratio to caclium usage (averaged across 30 commonly kept corals) thanks to the red sea studys. If there is interest (because it will take a bit of number crunching, coffees and swearing to get it done) we can show the level of delesion over periods of time using the most common 5%/week, 10%/week and 20%/month water changes?

you know your going to have to do that now :P