lduncan

Well my points started off simple enough: • 0.04ppm is not an extremely low phosphate level as far as corals are concerned. (Contrary to what the article implied) • Why spend money on an electronic meter when the reality is, they don't give you any more useful information than a normal test kit? • Phosphate test kits (including colorimeters) are useless for telling you how good phosphate levels are. They aren't accurate enough to do that. Instead you have to rely on bioindicators to monitor changes in phosphate below a certain point. The (impractical) alternative is expensive equipment. Then wasp started claiming stuff which was inaccurate, so then I presented the real information to support my point. Which was then dismissed as trivial babble. Presumably because no one actually understands what they mean, in which case, I question why some insist on disputing it? Layton

There is a lot of bullshit logic/advice/information spread in this hobby, some is harder to descern than other. Sometimes it takes someone who has some idea what to look for to spot it. Layton

People demand proof. Then when you give it to them they dismiss it at babble / insignificant / trivial. But it sure beat all the what ifs, mights, maybes etc

They also indicate that anecdotal evidence is only used as motivation for true research. Once that research is done and conclusive, anecdotal evidence becomes completely irrelevant... as is the case here. Why bother? This sort of statistical analysis has been done (extensively) for the PBM phosphate test method. Just ask the manufacturers. They prepare all this as part of the ISO 8466-1 standard certification. Typically: Standard Deviation of around +/- 0.035 mg/L Variation Coefficient of method +/- 1.5% 95% Confidence interval +/- 0.07mg/L Layton

Funny thing is, this thread probably would have ended up the same, if wasp hadn't persisted in making those inaccurate baseless claims. Layton

Convenient timing: http://www.reefcentral.com/forums/showt ... did=946479 These guys must be being argumentative for the sake of it too wasp, of course they're only saying that because they know you own one. :roll:

Then you of all people should know how wrong this is. Just remember what anecdotal means: And some reading: http://en.wikipedia.org/wiki/Anecdotal_evidence http://en.wikipedia.org/wiki/Availability_heuristic http://en.wikipedia.org/wiki/Neglect_of_Probability http://en.wikipedia.org/wiki/Endowment_effect I'm sure if anyone can show that the Hanna meter is more accurate than Hanna themselves say, they would be happy to hear from them. I'm sure they'd amend their marketing material in a second. Layton

Was the colorimeter calibrated?

It's not perfect, it's not even close, it's absolutely wrong. What he's saying is not helpful at all. It's absolutely misleading. Layton

But that doesn't make the conclusions you draw from those "experiments" correct. They are highly unscientific. Fundamentally flawed, and you can not draw the conclusion you have from the method you've followed. Hanna has stated the accuracy of there meter: +/- 0.04 +/- 0.01 +/- 4% of the reading. None of your experiments are rigourous enough to even start to dispute that. It shows your ignorance of scientific process, experimental technique, and testing principles The best reading you can get from a Hanna meter is 0.00 +/- 0.05ppm If you think otherwise, I'm sure Hanna would like to know. Also, you still haven't explained how the readings you get from a hanna meter are any more useful than those from a standard test kit. Layton

This just shows your total ignorance in this area. You can't make the claims you have made, from what you've done. It's so wrong it's not even funny.

I look at it this way. Calcium and potassium levels are similar in NSW. Calcium is mineralised in significant quantities (through calcification). Once it's been deposited, it generally doesn't get cycled through living tissue again. Potassium is used in cellular processes. It's not minerialised (at least not actively in significant quantities). In that sense you can think of it like phosphate. It's taken up by organisms, when the cells die, it's becomes available for other cells to use. It's cycled tightly in the system. There are no significant sinks of potassium. It doesn't go anywhere permanently. Given that, i would have thought it's more likely to accumulate rather than deplete in aquarium.

I thought that was the case. You're telling me that you don't believe the accuracy claims of the manufacturer, so you did your own "experiment" (I use that term loosely) and found that they are in fact far more accurate than Hanna claim. Then you proclaim this as if what you found is actually correct, and the Hanna's testing is wrong? We'll it might make sense to your mind, but unfortunately it's wrong. So tossing a coin you have 50% chance of getting heads right? Well i've just tossed a coin three times and got heads every time. So I now know that who ever said you get heads only 50% of the time is wrong, (because i have experience in tossing coins) that when you toss a coin, you will get heads 100% of the time. Also you still haven't explained how the readings from the hanna meter are any more useful than the ones you get from a standard test kit. Layton

Hope they've got some valid research to backup those claims. Somehow, i'm doubtful they do ;-) The zeoguide is hardly a reliable source for information of that sort. They are trying to sell a product, of course the blurb is going to try and entice people into thinking they need it. It's called marketing. Layton

It sure is. You can't kill corals doing that. Yip, and in tanks which have never run iron/aluminium based phosphate removers, iron/aluminium can sometimes cause problems initially.

You can add magnesium to that list too.

Funny thing is, you refused to answer that question then too. So, how did you test these kits? Layton

This is from the current zeo-guide: What are those two additional elements doing in there?

Well... how did you go about testing this.

Saying that K-Balance has those effects is different from saying potassium has those effects. There's more in K balance than just potassium. You shouldn't use the two interchangeably. There is no evidence to say that any effects you see from K-Balance are actually due to potassium in it, it could be due to the other constituents. Layton

Hach do a colormetric potassium test I think.

Well the fact is, you don't know what you're adding: I don't know how anyone could start to draw conclusion about potassium from using this when you don't even know what you're adding. First you have to establish at what levels potassium becomes limiting in these processes. Severely depleted, and limiting can be two different things. Do you have any evidence of any of those claims? Something to think about: Layton

The best possible reading you can get from a hanna meter is 0.00 right? That means that the phosphate level is anywhere between 0.00 and 0.05ppm right? So what does this tell you? Well not much. It could mean your phosphate levels are good, or it could mean you're phosphate levels are extremely high (0.05 is extremely high as far as corals are concerned). You have no way of knowing which it is. So for all intents and purposes this reading is useless. That's why you have to look at indicators within the tank to get an idea of how good your phosphate levels are. Compare this with a normal test kit can you tell the difference between the 0.05 and 0.00? (in low range)? Same deal, you could probably say that phosphate levels are between 0.00 and 0.05. Again this isn't particularly useful. Back to bioindicators. So I want to know how the Hanna meter provides any more useful information than a standard kit? It's not. Layton

So... what were the results. Provide some info to back that up. Their specifications say it. I'm not making things up at all. What possible agenda would I have? How did you test them? I'm not attacking Hanna. I'm simply saying that using a Hanna meter gives you no extra information than a standard test kit. It's no more useful than a standard kit.

I haven't seen any evidence of that, and like you've said, it's not exactly limiting, and not used in significant quantities. It's funny that no one in the hobby had bothered with potassium, until recently when a particular company started touting the dire consequences of potassium deficiency in corals, and how a new product from them could come to the rescue. Potassium isn't exactly an obscure element, so there was probably a reason no one had bothered with it previously ;-) Layton