Let's talk about the hanna meters....

[subielover]

Let me read up a bit on how the alk meters work and I will see if I can do the same (make some standards) for those.

That would be great, I have both checkers and can do some of the testing that is needed.

 

[ronnie]

My salifert ALK test kit comes with a standard. I'd assume that it is pretty close, as it tested about .2 off for me. Would that work in the checker?

Also - got my samples yesterday. I'll hopefully get a chance to test them here in a little bit.

 

[sowellj]

So while not everyone has received or run the samples I sent, the first results actually look pretty good. It would seem that if there are problems, then it is likely coming from something present in the tank. Additionally, it looks like their own meters are reproducible, i.e., the results for different meters aren't different for the same sample. To get to say a 0.05 ppm solution, you would take the 0.1 ppm standard and do a 1:1 dilution (5 mL standard, 5 mL RODI water). I would initially use DI for this instead of salt water. The reasoning being that if you still get a reading of 0 using a saltwater, you don't know if that is truly the LLOD (lower limit of detection) or if there is something in the saltwater competing with reagents consumption.

 

[ronnie]

I will give that a try as well sowellj.

What dilution would I use to get to .07? I'd like to try that as well.

 

[NeveroddoreveN]

I will give that a try as well sowellj.

What dilution would I use to get to .07? I'd like to try that as well.

7:3, not sure on that tho

 

[ronnie]

UGH!

Tested the .1 sample..... Came out at 2.05!

My question is this: I bought the 100 pack from TB Aquatics on eBay. They said that they work for the checker, as well as the original photometer. Is this correct?

The water was super blue when I checked it!

Faulty unit? Faulty test kit/wrong test kit? User error?

I dunno. When I get a chance I will test the other two as well. I have one original test kit left, I will use it.

 

[sowellj]

wow ronnie, that is rough. I can't comment on the user error side of things as I don't own one of these personally. I would try the other two and see what you get. With a reading that far off, I would first make sure that the cuvette is very clean and has no smudges on it. Since the meter works by measuring light absorption, smudges can cause scattering with will really mess things up I am guessing.

UGH!

Tested the .1 sample..... Came out at 2.05!

My question is this: I bought the 100 pack from TB Aquatics on eBay. They said that they work for the checker, as well as the original photometer. Is this correct?

The water was super blue when I checked it!

Faulty unit? Faulty test kit/wrong test kit? User error?

I dunno. When I get a chance I will test the other two as well. I have one original test kit left, I will use it.

 

[ronnie]

I cleaned the cuvette several times, but I will triple check it again.

I may try the other cuvette as well.

The thing that got me was how blue the water was with the .1 solution. At this point, I'm a bit leary of the reagents. I'll test it here in about an hour and confirm.

 

[Troylee]

Ouch!!!! I got a 100pk from socal tropical fish... I'll post a pic of the regent when I get home.... Gotta love technology lol... Walking the kiddies, trick or treating and surfing the net... Lol

 

[ronnie]

Here is what I bought:
100 HANNA INSTRUMENTS PHOSPHATE PHOTOMETER REAGANTS - eBay (item 270467486941 end time Nov-02-10 14:30:15 PDT)

 

[jcom]

I just got home from working on the stand for my new build and I'm too tired to run the tests, but will tomorrow. My sense from these posts is that it's not looking too good for the Hanna meters. No matter what, it looks like we'll all be left wondering, if even just a little, about the results. Bummer...

Got Utes!!! 8-0 #5 BCS (Let's get it right this year BCS....better yet, let's have a playoff!!!)

 

[ronnie]

Just tested twice with the 1.0 solution. Once with the provided reagent and then the 100pk reagent.

Got .94 w/provided and .91 w/100pk reagent.

Feeling a lot better about this thing now. Test with the .1 solution must have been user error.

 

[Troylee]

Here is the regent I got....

 

[skinz78]

You paid extra for the purple band huh?:xd:

 

[Oiseau Reefer]

My question is what's up with the different lot #'s

 

[ronnie]

My question is what's up with the different lot #'s

They probably make them at different times in small quantities to reduce the possibility of large batches being bad.

 

[ronnie]

Here is the regent I got....

That is what I got as well. The second time I tested, it was ok. It must have been something I did.

 

[Troylee]

You paid extra for the purple band huh?:xd:

That was extra... I had the packs in my hand and couldn't find a rubberband but of course my daughters leave there hair ties everywhere so it found a new home.... Lol :xd:

 

[skinz78]

LOL Troy, I feel your pain on that one, my daughter is the same way...

BTW I have the same regents too.

 

[HighlandReef]

my packs have green lettering and say lot # 008
i just tried my meter again and got a 0 but i have also been running gfo for about 3 weeks or so now, i did expect it to go down but was supprised when i saw 0
if i remember correctly it was .18 or something like that when i 1st started using the gfo on day 1
my meter did have a bad battery after only 2 tests and didnt notice it until i already mixed the reagent, i used both vials so didnt even think to check the meter until i was ready to start the test, i figure it was about 20 minutes or so to run to cvs and get more batteries, then ran test, i would think as long as i didnt open up the vials it shouldnt matter how long they sat but maybe i will try it again, gonna need more reagent... down to last two packs