lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 no, never tried one personally, but the reaction is the same, and photo diodes can be fooled by contamination and turbidity quite easily. I don't think they are worth relying on as a more accurate method. Just a guide. Hobby test kits can't tell you how good your phosphate is, just how bad it is. I don't take a undetectable readings as meaning phosphate is low, it just means it's not at eutrophic levels. Layton Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Oh I see about your hanna comments. You've never actually seen one. I own one. They are a world apart from a hobby kit. Your lack of experience will explain your remarks, as I suspected. All the other stuff you said about photo diodes or whatever, is a lot of theories you read somewhere. If you actually get to see a hanna and use one, I'll be happy to talk to you about them. Otherwise, don't see any point taking your advice on the subject. ( Trying to be gentle ) Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 Just because you've used one doesn't mean you know what it's doing and how it works. I don't have to physically use one to know how it works. The precision of the meters is only 0.01mg/L, with an accuracy of +/- 0.04mg/L. You can get similar accuracy from a salifert test. I guess because you're using an electronic device, it makes it "feel" more scientific and accurate. Layton Quote Link to comment Share on other sites More sharing options...
Brianemone Posted December 8, 2005 Report Share Posted December 8, 2005 come one guys it was going really well, pull your heads back in and keep on having civil discussions. those last few posts were very good, almost pleasant. :lol: anyway, other than the water quality do the sps benefit from the uv? (provide them with any food etc?) Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 anyway, other than the water quality do the sps benefit from the uv? (provide them with any food etc?) Bacteria and detritus, potentially, not sure though. My real aim is to avoid using carbon, and remove waste more efficiently. Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Just because you've used one doesn't mean you know what it's doing and how it works. I don't have to physically use one to know how it works. Layton Actually, you are right, I see it all now. I own & use one, so obviously would not know how it works. You, on the other hand, have never even seen one, and therefore are quite clearly in a much better position to make an informed assessment of the device. In fact, I am so impressed with your almost telepathic abilities, that I am going to award you my 10/10 award, for the person most able to know everything about everything, and form a valid, strong opinion, even on devices still unseen. In honor of your remarkeable talent, I now extend you a cordial invitation, to send me a sample of your tank water. The address is 9 Ronald Macken Place Mairangi Bay Auckland 1311 The water will be tested for PO4, with the Hanna. We will then be able to find out what your orthophosphate REALLY is, wether your hobby kit is REALLY accurate, and I'll even be able to tell you how often you REALLY clean your glass. Looking forward to it. Just one thing though, I'd like the water sample to be taken from your tank under supervision of a neutral person on this site. Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 You still don't get it do you. It is possible to know how something works without ever using it. It is also possible to use something without even knowing how it works. Tell me how the Hanna meter works, what it's constructed from, the physics behind it's operation. Explain what has to potential to bias the readings you get from it. Then explain to me how you can trust a reading from a device of 0.02 (when the accuracy of it is only +/- 0.04) more than the salifert test kit. The true value could lie anywhere between 0.06 and 0.008 Explain the difference to me between precision and accuracy. Salifert test kits and the Hanna meter are of similar usefulness. Just because there is an electronic device giving you a number does not necessarily make it more accurate. Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Just send me the water Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 as usual can't answer the questions. Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Your water will answer all the questions I need Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 humour me, answer mine for once. Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 No need. You clearly already know everything. Just send me the water. I have a few questions I'd like answered Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 Tell me how the Hanna meter works, what it's constructed from, the physics behind it's operation. Explain what has to potential to bias the readings you get from it. Then explain to me how you can trust a reading from a device of 0.02 (when the accuracy of it is only +/- 0.04) more than the salifert test kit. The true value could lie anywhere between 0.06 and 0.008 Explain the difference to me between precision and accuracy. Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 No need. You clearly already know everything. Just send me the water. I have a few questions I'd like answered Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Well, that seems to have put perspective on the usefulness of theories against practise :lol: Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 :roll: yet more personal attacks and assumptions from people who don't know what they are talking about. Can you guys not discuss something civilly, without having to resort to slinging mud when I ask a few questions. You really should grow up. Layton Quote Link to comment Share on other sites More sharing options...
Pies Posted December 8, 2005 Report Share Posted December 8, 2005 Can you guys not discuss something civilly, without having to resort to slinging mud when I ask a few questions. hahahaha. You do a bit of slinging and bating youself. Piezola Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Just wonder why you have to launch such an attack on the Hanna meter anyway? Is it just that I've got one? Lets face it, you've never seen one, but you confidently disparage the device anyhow. Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 Just wonder why you have to launch such an attack on the Hanna meter anyway? Is it just that I've got one? Lets face it, you've never seen one, but you confidently disparage the device anyhow. It's not an attack, the manufacture gives it's precision and accuracy. Plus if you know how they work, then you can see why they have the accuracy they do. All i've said is that it's no more useful in getting accurate measurements than Salifert kits. This "confident disparagement" comes directly from the specifications of the device, coupled with a knowledge of how it works. How about answering my questions: What's the difference between precision and accuracy? (This is fundamental in interpreting any measured value) Layton Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 Just send the water. Lets see if the reality matches the hype! Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 still can't answer the questions... How can you have an opinion on the accuracy of the device, without knowing what the specifications are, or how it works? Layton Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 ... Or even the difference between precision and accuracy for that matter. Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 How can you have an opinion on the accuracy of the device, without knowing what the specifications are, or how it works? Layton Yet another one of your bold ASSUMPTIONS Layton, once again not based on reality I'm sorry to say. Fact is I do know what the specs are, and I do know how it works. Quote Link to comment Share on other sites More sharing options...
lduncan Posted December 8, 2005 Author Report Share Posted December 8, 2005 How do you interpret that then. What is the most accurate reading you can get from it? Quote Link to comment Share on other sites More sharing options...
wasp Posted December 8, 2005 Report Share Posted December 8, 2005 just send the water Quote Link to comment Share on other sites More sharing options...
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