Which hanna phosphate checker?

[w2inc]

There are a bunch of models. What is the most appropriate one for monitoring phosphates at reef levels?

 

[MabuyaQ]

HI-736

 

[SuncrestReef]

HI-736

I agree, the Hanna Ultra Low Range Phosphorus checker is the way to go. I use it daily on my tank and my PO4 is currently measured at about 0.05 ppm.
https://www.bulkreefsupply.com/phos...eter-hi736-hanna-checker-hc-marine-water.html

 

[LilElroyJetson]

Yup. The ULR is the only one that should be used if you’re trying to keep your phosphate within the generally desirable range of <.03 (although many don’t worry as much about phosphates that are a little higher). The standard Hanna Phosphate checker has a margin of error of .04 ppm, so it could be reading .03 and your phosphates really might be .07. The ULR gives much more accurate readings in the desired range we are most concerned with.

EDIT: Did not realize when I made this post Hanna recently released a second Phosphate ULR checker, addressed below.

 

[w2inc]

Thanks guys, just bought one.

 

[LilElroyJetson]

Thanks guys, just bought one.

Anytime. Great investment!

 

[Bigboned]

Is the HI-774 not the ULr phosphate checker?

 

[LilElroyJetson]

Is the HI-774 not the ULr phosphate checker?

They both are ULR. The difference between the HI-736 and the HI-774 is that the 736 range is 0-200 ppb and the 774 is 0-0.90 ppm. The HI-736 will be more precise in the low range we are concerned with and the one that should be used if trying to maintain below .03 ppm. The margin of error on the 736 is 5 ppb, so the checker could show .031 but the true reading might be .046, so accurate enough although not perfect, but it will be more accurate in the ultra low ranges where the 774 won’t be. The 774 has a margin of error of .02 ppm, which is a similar margin of error as the 736 but the 736 will be more accurate closer to 0 ppm, which is what we want. I believe Hanna recently came out with the HI-774 for ease of getting readings in ppm for the marine hobbyist without having to convert ppb to ppm, but just speculating. I think this because it is not much less accurate (or any more accurate), than the HI-736.

 

[Reefahholic]

ULR! 736

 

[Reefahholic]

They both are ULR. The difference between the HI-736 and the HI-774 is that the 736 range is 0-200 ppb and the 774 is 0-0.90 ppm. The 774 will be more precise in the low range we are concerned with, however if your phosphate is ever over .90 ppm, you won’t know what it is, so somebody with extremely high phosphates won’t find much use in the 774. You are correct though, the HI-774 is the one that should be used. If phosphate is over .9 that is extremely high. The margin of error on the 736 is 5 ppm, so the checker could show .031 but the true reading might be .046, so accurate enough to get the job done but the 774 is preferred.

Is that a typo? The 774 will be more accurate in the higher range right.?

The 736 is the ULR and will be more accurate in the lower range I believe.


Ohh wait....I see what you mean.

Most people run below 0.6 so I'm not sure why you would want to buy anything other than the ULR unless your PO4 is sky high.

Only Richard Ross uses the 774.

 

[infinite0180]

Isnt the 774 the one that they just came out with? My understanding is the 774 is the same as the 736 just does the conversion to ppm for you and it has a longer time before it turns off automatically...

The 713 is the bad one...

 

[LilElroyJetson]

Is that a typo? The 774 will be more accurate in the higher range right.?

The 736 is the ULR and will be more accurate in the lower range I believe.


Ohh wait....I see what you mean.

Most people run below 0.6 so I'm not sure why you would want to buy anything other than the ULR unless your PO4 is sky high.

Only Richard Ross uses the 774.

No, that was a good catch, thank you! I confused myself looking at the spec sheets on Hanna’s website! I re-worded my above post, but while the margin of error for each checker is actually close and either should get the job done, the 736 becomes more accurate at that ultra low range because it’s measured in ppb, so while at a higher ppb the readings may not vary much between the 736 and 774, at the lower range closer to 0 ppm, that more precise reading will be more helpful for those looking to strictly keep phosphates below .03. The 774 margin of error of .02 would be too much to trust.

For example:
HI-774 reads at .03 ppm, it could be .03 ppm, but also could be .01 ppm or even as high as .05 ppm.

HI-736 reads at 10 ppb (or .031 ppm), it could be accurate but it could also be 5 ppb (.015 ppm) or even 15 ppb (.046 ppm). This example is why I was saying the margin of error is similar. The 736 margin of error, in this example, is not far off from the 774, but it matters more the closer you want your phosphates to zero. And I’m a nerd lol.

With all that being said, either will do just fine for most people, with the 736 maybe more suitable to those keeping an ULNS.

Here’s the conversion chart for PPB to PPM if anybody wants to peek at it:

 

[Reefahholic]

No, that was a good catch, thank you! I confused myself looking at the spec sheets on Hanna’s website! I re-worded my above post, but while the margin of error for each checker is actually close and either should get the job done, the 736 becomes more accurate at that ultra low range because it’s measured in ppb, so while at a higher ppb the readings may not vary much between the 736 and 774, at the lower range closer to 0 ppm, that more precise reading will be more helpful for those looking to strictly keep phosphates below .03. The 774 margin of error of .02 would be too much to trust.

For example:
HI-774 reads at .03 ppm, it could be .03 ppm, but also could be .01 ppm or even as high as .05 ppm.

HI-736 reads at 10 ppb (or .031 ppm), it could be accurate but it could also be 5 ppb (.015 ppm) or even 15 ppb (.046 ppm). This example is why I was saying the margin of error is similar. The 736 margin of error, in this example, is not far off from the 774, but it matters more the closer you want your phosphates to zero. And I’m a nerd lol.

With all that being said, either will do just fine for most people, with the 736 maybe more suitable to those keeping a ULNS.

Here’s the conversion chart for PPB to PPM if anybody wants to peek at it:

Good info man!

 

[LilElroyJetson]

Good info man!

Thanks, @Reefahholic! ;Bookworm I hope I didn’t get too deep in the weeds and cause more confusion than help, but all the posts in here taken together should help those deciding between the two with their decision: a slightly higher degree of accuracy (HI-736) vs. not having to do any conversion and being fine with getting close enough (HI-774).

 

[w2inc]

Thanks for pointing me in the right direction people. I do think that there was a typo somewhere above. Left me wondering if I got the right one and I gave in and did some more research. I landed back at the original decision for the HI736.

It is the HI713, Low range checker (mentioned above) that has the ±.04 ppm margin. This one would not be very useful in trying to maintain phosphate under .03 and above .01, which was my goal.

There are two Ultra Low range checkers available from BRS:

Phosphate: HI774 accuracy ±.02 ppm
Phosphorus: HI736 accuracy ±.015 ppm (reads phosphorus ppb and requires manual conversion to phosphate ppm)

These would both work. Which is better?

I would always like more accuracy, but a big part of my reasoning in getting the Hanna checker was ease and convenience. One vial and one package with no color guesswork is pretty attractive. When I look at my ICP results compared to my notebook results from my Salifert kits, I am not far enough off to make me terribly concerned. Regarding phosphate, I might even be as accurate as the 713 and that has kept my animals alive for the past 3 years. This leaves me sitting on the edge of the decision since I would rather not do math with each test.

I decided to just get use to working in ppb and take the HI736. I will just try to shoot at the 16 ppb to 6 ppb range (.049 to .018 ppm phosphate). After accounting for the tolerance it will let me know that I have some, at least .oo3 ppm, but less than .064 ppm in my system. I don't think a tank is going to crash over a .005 po4 error. It is easy to see why many people recommend the HI774.

Chime in if I am wrong. Thanks again for all the feedback.

 

[infinite0180]

Thanks, @Reefahholic! ;Bookworm I hope I didn’t get too deep in the weeds and cause more confusion than help, but all the posts in here taken together should help those deciding between the two with their decision: a slightly higher degree of accuracy (HI-736) vs. not having to do any conversion and being fine with getting close enough (HI-774).

Thank you! Im about to buy one and this breaks it down for me! Also the new 774 gives you a longer time before it powers off automatically allowing you to add reagent without feeling rushed!

 

[LilElroyJetson]

Thanks for pointing me in the right direction people. I do think that there was a typo somewhere above. Left me wondering if I got the right one and I gave in and did some more research. I landed back at the original decision for the HI736.

It is the HI713, Low range checker (mentioned above) that has the ±.04 ppm margin. This one would not be very useful in trying to maintain phosphate under .03 and above .01, which was my goal.

There are two Ultra Low range checkers available from BRS:

Phosphate: HI774 accuracy ±.02 ppm
Phosphorus: HI736 accuracy ±.015 ppm (reads phosphorus ppb and requires manual conversion to phosphate ppm)

These would both work. Which is better?

I would always like more accuracy, but a big part of my reasoning in getting the Hanna checker was ease and convenience. One vial and one package with no color guesswork is pretty attractive. When I look at my ICP results compared to my notebook results from my Salifert kits, I am not far enough off to make me terribly concerned. Regarding phosphate, I might even be as accurate as the 713 and that has kept my animals alive for the past 3 years. This leaves me sitting on the edge of the decision since I would rather not do math with each test.

I decided to just get use to working in ppb and take the HI736. I will just try to shoot at the 16 ppb to 6 ppb range (.049 to .018 ppm phosphate). After accounting for the tolerance it will let me know that I have some, at least .oo3 ppm, but less than .064 ppm in my system. I don't think a tank is going to crash over a .005 po4 error. It is easy to see why many people recommend the HI774.

Chime in if I am wrong. Thanks again for all the feedback.

You’ve got it right. If you’re not running an ULNS (ultra low nutrient system), you will be just fine with the 774. Personally, it is my opinion that the more accurate model is preferred but we’re really splitting hairs at that point. Personal preference.

 

[LilElroyJetson]

Thank you! Im about to buy one and this breaks it down for me! Also the new 774 gives you a longer time before it powers off automatically allowing you to add reagent without feeling rushed!

Honestly, using the spreadsheet posted above, I really don’t find the conversion an issue. I keep it on my phone and pull it up when I’m testing and it’s a quick glance to convert. I cut the reagent packet open before I begin, drop 10 ml of water into a vile, run the zero, then dump the packet in, shake for 2 minutes, hold the button down and let the checker use the internal 3 minute count down timer and give me a reading. Cutting the reagent packet open and taking a long time to do it is the only step that I think would cause it to time out, and because I do this in advance because I want to complete testing as quickly as possible anyway, I never have the device time out on me. Makes for much more efficient testing. However, the 774 is easier to use especially when you don’t have the conversion chart simply because it eliminates the need to look at the chart, and is more relaxed/fool proof because of the longer time before it automatically turns off, so I see the appeal.

PS - I’m more than happy to send anybody using the HI-736 who needs the conversion chart the high resolution pdf version of it.

 

[infinite0180]

Honestly, using the spreadsheet posted above, I really don’t find the conversion an issue. I keep it on my phone and pull it up when I’m testing and it’s a quick glance to convert. I cut the reagent packet open before I begin, drop 10 ml of water into a vile, run the zero, then dump the packet in, shake for 2 minutes, hold the button down and let the checker use the internal 3 minute count down timer and give me a reading. Cutting the reagent packet open and taking a long time to do it is the only step that I think would cause it to time out, and because I do this in advance because I want to complete testing as quickly as possible anyway, I never have the device time out on me. Makes for much more efficient testing. However, the 774 is easier to use especially when you don’t have the conversion chart simply because it eliminates the need to look at the chart, and is more relaxed/fool proof because of the longer time before it automatically turns off, so I see the appeal.

PS - I’m more than happy to send anybody using the HI-736 who needs the conversion chart the high resolution pdf version of it.

Man i was thinking i was going to go with the 774 but it sounds like the 736 is actually the better option...

 

[LilElroyJetson]

Man i was thinking i was going to go with the 774 but it sounds like the 736 is actually the better option...

Haha I think so, but like I said, you really can’t go wrong either way. Just comes down to what you prefer. Let us know what you decide!