really nice low tech reef, TOTM @reefs,org

[lduncan]

At least someone's following this.

Layton, from my understanding reading this thread is that orthophosphate is a very strong oxydiser and will practically be consumed as soon as it appears. This means that we will only measure orthophosphate when we have more total phosphate in the system then that the bioload needs / can handle. This does indeed mean that as soon as we can measure it we do have too much.

You can think of orthophosphate (or reactive phosphate) as a strong oxidiser (in reality it's not in terms of chemistry) in a biological way bacteria and phyto use it. Many bacteria have evolved to take up phosphate in excess of what they need to live and reproduce. Of course there is a limit to what they can store, once that limit is reached they are saturated. So then as more orthophosphate enters the system, it can happily hang around without being consumed.

Think of it just like ammonia. When you cycle the tank in the beginning ammonia is detectable because the bacteria which are present are in saturation, they are processing it at their limit. Once the tank has cycled, ammonia is undetectable because bacteria are consuming as fast as it's being created. Ammonia is still present in the tank, but for all intents and purposes it does not exist.

As soon as you can measure any phosphate with any kit available in the hobby, your tank has many times the amount of phosphate required by any of the inhabitants.

Wasp, what method do you use to measure orthophosphate? What numbers do you get and what is the accuracy of the method (not only the meter). In my line of work I am always very carefull with measument numbers. Customer often ask me how much is in a sample and if you give them a number that ill be used a fixed without looking at how that number is established. When testing such small quatities lots of things have to be taken into account besides the test itself. Like sampling method / stability of sample between sampling and testing / all kind of ways to get the sample contaminated and the list goes on. We do certain testing and the results might be +/- 30% but nobody that takes that into account. Not all testing is fact. Only testing where everything is taken into account and we understand the meaning of the result.

Jeroen.

Exactly. This is a point which I've tried to make with wasp before. It seems to have fallen on deaf ears.

The colorimeter he uses to test phosphate has an accuracy of +/- 0.04 mg/L plus +/- 4% of the reading, plus and EMC deviation of +/- 0.01.

So just like every other test kit, it can only tell you how bad your phosphate levels are, it doesn't have the accuracy or even resolution to tell you how good they are.

Layton

[suphew]

Layton, I'm supprised your still pushing this. I'm not saying the theory is incorrect, I dont anything about it to say one way or the other, but there is a serious flaw in the logic of your last few posts.

[wasp]

Me Stubborn! Well I guess I sometimes get that way when I'm right :lol: :lol:

All I'm saying is there's orthophosphate in every tank, and since Layton has now admitted this ( It was like pulling teeth though) I don't know why the argument still continues.

However for Jeroens information, the instrument i use is a Hanna colorimeter, regarded by everybody except Layton as the best available to the hobby. The claimed accuracy is +/- 0.04 mg/L plus +/- 4% of the reading, plus and EMC deviation of +/- 0.01, which in real life exceeds anything else sold to the hobby. However, in fact, I have found the tolerances much better than that, as can be established by doing multiple tests on the same sample, I have found it highly accurate, it is great to see manufacturers conservative in their claims.

BTW Layton has a lot to say about how worthless Hanna colorimeters are, in reality he's never even seen one

If I test garuanteed nil phosphate water, such as RODI, I will always get a zero reading. I have never had a zero reading from any reef tank.

But hey, amazing how such a small thing can turn into pages of argument.

Because sticking to what I know is the facts is just being stubborn, I'll leave it there, unless Layton comes out with anything else really outlandish that is too hard to resist!

And saying orthophosphate does not exist in a reef tank IS outlandish, it's impossible!

[lduncan]

However for Jeroens information, the instrument i use is a Hanna colorimeter, regarded by everybody except Layton as the best available to the hobby. The claimed accuracy is +/- 0.04 mg/L plus +/- 4% of the reading, plus and EMC deviation of +/- 0.01, which in real life exceeds anything else sold to the hobby. However, in fact, I have found the tolerances much better than that, as can be established by doing multiple tests on the same sample, I have found it highly accurate, it is great to see manufacturers conservative in their claims.

BTW Layton has a lot to say about how worthless Hanna colorimeters are, in reality he's never even seen one

All I've said is that they aren't any more useful than any other kit available. Even if it was as accurate as it's precision, then the best you could say is that phosphate is below 0.01mg/L . This tells you that you have a large excess of phosphate in your tank. It doesn't tell you how good your phosphate level is.

If I test garuanteed nil phosphate water, such as RODI, I will always get a zero reading. I have never had a zero reading from any reef tank.

That's the thing you can't garuantee it. So how do you know that the actual level is not 0.05mg/L? Based on the specifications for the device, that could well be the true reading given the display showing 0.00, you have no idea what the true reading is, just that it's below 0.05mg/L. That's the very reason for these error ranges! It's because you can't just pretend that the number on the display is the true number. If you could, then the accuracies would reflect this.

But hey, amazing how such a small thing can turn into pages of argument.

It's only page two. Hyperbole don't you think?

And saying orthophosphate does not exist in a reef tank IS outlandish, it's impossible!

As usual your own little argument going on in your head. Who said orthophosphate does not exist in a reef tank? I didn't.

Layton

[Sharkey]

Can someone clarify what we are talking about when we are talking about orthophosphate? when I do a search I cant anything that makes sense? .And why is it important? And getting back to the start of the thread I guess its all coming back to basically the DSB vs. BB Debate right ?Can a Dsb control phosphate the answer is yes it can. Can it do so for a long time This is the one that we will always have debate about. All I can say is yes it can work long term but indefinitely that's a good question and you will find healthy debate after all we have closed system it has to go somewhere right?Or is it a closed systeem if we are doing water changes at 40% as the tank of the month is. I've run a DSB for almost three years and have had no problems so personal experience says yes and from what I have read from some very experienced people yes it can there are tanks that are ten years plus with a DSB nutrient sink or not that's the whole real question isn't it?Time bomb or aid to the hobby?

[JoeBlog]

the instrument i use is a Hanna colorimeter

Wasp, I've been using Salifert (always totally clear). I'm a bit curious about this test kit. May I ask where you get them from, how much it is and how many tests you can get out of it?

Cheers, Steve

[lduncan]

Orthophosphate, reactive phosphate, inorganic phosphate whatever you want to call it, is the only form of phosphorous which hobby test kits measure. It is the molecule PO4-3.

It's the form of phosphate which is not part of an organic molecule like polyphosphate.

Layton

[wasp]

As usual your own little argument going on in your head. Who said orthophosphate does not exist in a reef tank? I didn't. Layton

Now you really are being silly Layton. The only thing I've been saying throughout is that "orthophosphate exists in all tanks", and you've responded with post after post of scientific sounding argument, and quotes from articles, attempting to prove me wrong ( as always ). :lol:

Trouble is there is not one thing in what you have said that actually does prove me wrong, which is why I've not bothered to debate any of it. I’ve simply restated the fact that “orthophosphate exists in all tanksâ€. If there really was anything out there that proved me wrong, I'm sure you would have found it. But you haven't been able to. Does that tell you anything?

Wasp, I've been using Salifert (always totally clear). I'm a bit curious about this test kit. May I ask where you get them from, how much it is and how many tests you can get out of it?

Cheers, Steve

Hi Steve, Always thought it was Joe!

To get a Hanna digital colorimeter you would have to import it, or ask one of the marine importers to specially bring one in for you. Which they will do, Reef uses one of these himself. They are battery operated so power supply is not an issue. Not sure on cost now but maybe somewhere around NZ$400.00. Once you have the actual unit, the ongoing running costs are cheaper than using something like a Salifert, just the initial cost is high. But to me, it was not about money but more about accuracy now I am using zeovit and need a fairly precise reading at low levels. I will add though I’m not here to sell them, I’m very happy with it, there is obviously at least one person here who has decided they are rubbish, each to their own, do I care? No.

Can someone clarify what we are talking about when we are talking about orthophosphate? when I do a search I cant anything that makes sense?

Hi Sharkey, to give Layton his due his chemical formulas are correct. Just that to some people myself included a whole bunch of chemical formulas can get a bit meaningless, good to have though.

So in the language of common folks like me, orthophosphate could be called “free†phosphate, floating around in the tank, waiting to bind with something or be used by some living creature. So in many tanks, most of the phosphate will already be bound, either chemically onto the surfaces of substrate etc, or being held within living organisms such as corals and algae, all living organisms need phosphate.

Why is it Important? Well it is very, because it is needed for life, and too little of it can starve corals and damage them, Layton will dispute that but that’s my belief. Too much of it is also harmful, in three main ways, 1. Fuelling unwanted algae growth, and 2. Interfering with calcification as corals are trying to grow. Coral skeletons are built of calcium carbonate, but if there is excess orthophosphate in the water some of it will bond to the surface of the calcium carbonate and slow down / stop further calcification, so corals can’t grow. 3. Too much orthophosphate can also over stimulate the corals zooxanthellae, causing the coral to lose the ability to regulate them and making the corals brown and unhealthy, if this condition is kept long enough the coral may even die.

So the testing dilema is that we can only test the water for orthophosphate, as phosphate that is bound chemically to substrate or held in algae or suchlike, obviously cannot be tested. This is where the two different viewpoints come from, one viewpoint ( Laytons ) being that as much phosphate may be in a bound form in the tank, testing the “free†phosphate is relatively meaningless as it does not tell the whole story. The other viewpoint ( mine ) is that at least some useful information can be had by testing the free phosphate.

[lduncan]

Now you really are being silly Layton. The only thing I've been saying throughout is that "orthophosphate exists in all tanks", and you've responded with post after post of scientific sounding argument, and quotes from articles, attempting to prove me wrong ( as always ). :lol:

Trouble is there is not one thing in what you have said that actually does prove me wrong, which is why I've not bothered to debate any of it. I’ve simply restated the fact that “orthophosphate exists in all tanksâ€. If there really was anything out there that proved me wrong, I'm sure you would have found it. But you haven't been able to. Does that tell you anything?

I was clear from this post that you missed the point completely:

But phosphate can continue to be bound until the tank is a complete block of phosphate. Prior to that, there will always be somewhere for phosphate to go. But still we have orthophosphate. Explain that.

...

However, to say that orthophosphate does not exist unless all other "sinks" as you call it, are "totally saturated", would mean that the subject tank of this thread, having measureable orthophosphate, must be "totally saturated", in other words, right on the brink of a crash, as we speak. As it is "totally saturated", there is nowhere left for any phosphate to go, and so as phosphate is added via feeding, this can only become orthophosphate and we may fully anticipate this tank crashing within the next few weeks.

You mis-understood from the get go, which is why I have persisted. I've said that for all intents and purposes orthophosphate doesn't exist unless all sinks for it are full. You've taken that literally, and said that it means that it has to be absolutely zero, not a single molecule of it around. I've qualified it say it means zero like ammonia is zero, ie there will always be some in transition from when it's added or produced until it's found and used by bacteria and phyto. This takes a finite amount of time to happen. This level is well below anything testable by you. Again for all intents and purposes it does not exist in this situation.

But to me, it was not about money but more about accuracy now I am using zeovit and need a fairly precise reading at low levels.

You know they use the exact same test method and reagents as the Salifert test don't you? They are not accurate enough to be any more useful.

Why is it Important? Well it is very, because it is needed for life, and too little of it can starve corals and damage them, Layton will dispute that but that’s my belief.

Well in order to starve corals of phosphate, first you would have to get phosphate to a point where it is severely limiting (that's total phosphate, not just orthophosphate). To do this of course you'd have to be able to test levels which are orders of magnitude lower than what we are capable of. You would then have to hold it there while the corals deplete there internal pools, then you may stunt the growth, and if it's low enough kill them.

I don't dispute that. What I do dispute is the arbitrary number which wasp has stuck on there, 0.02 mg/L (or whatever it was) of orthophosphate. It's rediculous, coral don't require anywhere near that amount. Eutrophication limits are determined to be around 0.003 mg/L of TOTAL phosphate, which is a lot lower than 0.02, and corals require even less than this level.

Also don't mistake orthophosphate for bio-available phosphate, they are different.

So the testing dilema is that we can only test the water for orthophosphate, as phosphate that is bound chemically to substrate or held in algae or suchlike, obviously cannot be tested.

Hach do a test kit for total phosphate. You need to be able to boil strong mineral acids, in order to break bound phosphate into orthophosphate.

This is where the two different viewpoints come from, one viewpoint ( Laytons ) being that as much phosphate may be in a bound form in the tank, testing the “free†phosphate is relatively meaningless as it does not tell the whole story. The other viewpoint ( mine ) is that at least some useful information can be had by testing the free phosphate.

There are two useful pieces of information which can be gather from our phosphate test.

1. Phosphate is high.

2. Phosphate is ridiculously high.

wasp, consider this, what are the two possibilities if bacteria or phyto come into contact with orthophosphate?

what are the possibilities if they run into polyphosphate?

Layton

[cracker]

depends how big it is.

If its small, they might just trip over, if its big they actually might hurt themselves!

:lol:

[wasp]

It's sad Layton that you have to argue with every last thing I say, it's a habit with you. To read your last post, a person would think that just about everything I had said was wrong. In fact there is not one thing in the post you criticised that is incorrect.

And to justify your own mistakes you keep re-qualifying what you say, and pages of argument and fudging. For example this -

I've said that for all intents and purposes orthophosphate doesn't exist unless all sinks for it are full. Layton

"For all intents and purposes" ? You never said that at all. What you said was literal, and that's how me and everyone else took it.

If what you said was not literal, you would not have had to spend 3 pages arguing and fudging trying to defend your position, would you? :lol:

And nor would you have needed to be so intent on trying to prove what I said was wrong, if you had not in fact said the opposite, would you? :lol:

Sadly you ar playing with words again, I have during the thread tried to meet on our common ground, something you are never prepared to do. I knew you would argue with what I said and I said you would, and of course I was correct.

If you made a mistake, or let's be kind and say you were not clear, you should fess up, not spend 3 pages trying to fudge it.

[lduncan]

I admit it was not absolutely clear. However you still don't seem to have grasped the concept.

Also if you had a deeper understand of phyics, chemistry and scientific process in general, you'd soon realise that these sorts of simplified statements are commonly made, when you delve deeper you find that technically they are incorrect, but they still serve a useful purpose. You can't always explain every single little detail when you're trying to get across a concept.

You've obviously taken it literally, maybe because it's convenient for argumentative reasons.

Layton

[wasp]

You've obviously taken it literally, maybe because it's convenient for argumentative reasons.

Layton

Yes I'll admit I can be argumentative when I'm right.

But really my issue was with this statement, said when you were critisizing the lovely reef that was the subject of this thread.

I wouldn't consider 0.024mg/L particularly low, considering the nature of phosphate.

Layton

You don't understand this is quite a common, even better than average, level in an average reef tank if tested with an accurate device. Not ideal I'll give you, but nonetheless, the way it is. I know many people think their orthophosphate level is zero, that's because that's what their Salifert kit tells them.

I also know you dissagree with that, so when I offered to test your own water, you switched to critisizing the instrument I use, the best commonly available to the hobby.

Yes the Hach is good, but who is going to dissolve the contents of their tank in acid to see how much bound phosphate was there? :lol: Only a small sample can be tested and the resultant number will not be of great practicle value.

However you and I will never agree on any of this. I accept that. But considering all the phosphate related problems you've had, including RTN, and being forced to completely strip your tank and spend months cleaning up your rocks, I'll just do things my way in regard to phosphate, thank you.

Not to mention the disaster when you tried to use Zeovit, again caused by not properly understanding phosphate. But instead you now blame the Zeovit. Laughable.

OK, so that was pretty vicious but that's how I see it. Now you can pull everything I said apart as you always do, but you won't catch me adopting your theories and methods.

[lduncan]

But really my issue was with this statement, said when you were critisizing the lovely reef that was the subject of this thread.

Ahh, the line right before I criticised the tank saying:

However the tank does look nice. But then I've never said you can't have a nice looking tank with a sand bed.

What I said was a valid criticism. It's not particularly low. In fact it's a level which is close to 10 times the upper limit researches use as indicator on the reef of significant changes for the worst happening.

You don't understand this is quite a common, even better than average, level in an average reef tank if tested with an accurate device. Not ideal I'll give you, but nonetheless, the way it is.

I completely understand this is within a common reading range. However that does not make it a low reading in my opinion. A low reading is not relative to other tanks, it's relative to what is required by the animals you're keeping.

I know many people think their orthophosphate level is zero, that's because that's what their Salifert kit tells them.

And I know people who think their orthophosphate level is 0.02 because a electronic meter told them it is. Both these people are wrong.

I also know you dissagree with that, so when I offered to test your own water, you switched to critisizing the instrument I use, the best commonly available to the hobby.

Because you consider it to be the best commonly available, doesn't make it useful for the purpose you're trying to use it for here.

Yes the Hach is good, but who is going to dissolve the contents of their tank in acid to see how much bound phosphate was there? :lol:

You do it already every time you do a phosphate test with your Hanna meter.

Only a small sample can be tested and the resultant number will not be of great practicle value.

It would actually be of more value than the orthophosphate reading. But the test is not exactly practical for a hobbyist to perform. Especially if they have no knowledge of the chemicals involved.

But considering all the phosphate related problems you've had, including RTN, and being forced to completely strip your tank and spend months cleaning up your rocks, I'll just do things my way in regard to phosphate, thank you.

What I consider a phosphate problem and what you consider a phosphate problem are two different things. In all the years I've been running tanks, i've only had a two week period where I could detect phosphate in my water at all, every other time, it's been undetectable. I wasn't forced to completely strip down my tank. I've not had massive problems with hair algae, only small isolated patches, mainly on newly introduced rock.

So relative to other people I haven't had significant phosphate related problems. Hell i've never even used phosphate remover!

Not to mention the disaster when you tried to use Zeovit, again caused by not properly understanding phosphate. But instead you now blame the Zeovit. Laughable.

What didn't I understand about phosphate that cause zeovit to be a disaster? I didn't lose any corals when I used it. I could see that zeovit was causing changes in my tank, which were not what I wanted happening.

Layton