Calcium test results from AWT -- HELP!

[Goodwin9]

I tried Aquarium Water Testing for the first time to double check my own testing. I got this report from them yesterday and had a big difference in the calcium results as compared to mine. I tested the same water I sent to AWT and had a calcium reading of 450, theirs came back much lower. I used the Salifert test kit for my testing. This afternoon, I took a water sample to the LFS and they tested 470, here again using a Salifert test kit. Does any have experience with AWT that had the same problem, or is Salifert not the best test kit I should be using for measuring my calcium levels. Any help would be appreciated!

 

[luke33]

All i can say is salifert test kits as of lately have been waay off imo. The calc and alk have had major QC issues. I'll never buy or trust one again.

 

[Goodwin9]

<a href=showthread.php?s=&postid=11003900#post11003900 target=_blank>Originally posted</a> by luke33
All i can say is salifert test kits as of lately have been waay off imo. The calc and alk have had major QC issues. I'll never buy or trust one again.

I am curious which one you are now using... I am planning on sending off another water sample from one of my tanks which tests out about 450 CA using Salifert. It will be interesting to see if I get the same low calcium reading back from AWT.

 

[USC-fan]

How did you get to that summary page at AWT?

 

[Mavrk]

<a href=showthread.php?s=&postid=11004160#post11004160 target=_blank>Originally posted</a> by USC-fan
How did you get to that summary page at AWT?

it looks like a scan of the report

 

[bertoni]

Hard to say. I haven't had any problems with my Salifert Ca test kits, but perhaps I've been lucky. Since I don't know how AWT treats the test sample, I'm not sure how accurate their testing would be.

 

[USC-fan]

<a href=showthread.php?s=&postid=11004381#post11004381 target=_blank>Originally posted</a> by Mavrk
it looks like a scan of the report

the report i get looks nothing like that.

 

[Billybeau1]

I too have not had any problems with my Salifert Ca++ kit. Even compared to another kit.

I would question what method this company uses to test calcium.

 

[Goodwin9]

<a href=showthread.php?s=&postid=11005147#post11005147 target=_blank>Originally posted</a> by USC-fan
the report i get looks nothing like that.

The report I got from AWT was sent to me in a PDF format, I printed the report and scanned the first page so that I would be able to post on the forum. If you send me your email, I will send you the complete report as sent to me by AWT.

 

[luke33]

Check out the issues in the salifert sponsors forum for all the info on bad kits around. If its a fairly new kit, it may be one of the bad one's.

 

[Goodwin9]

I wrote to AWT and asked about the difference in the CA test results and thought that I would post the reply I received back from AWT.

Hello Chuck,

Thank you for writing. I know that the calcium test uses an ion-selective probe and I have asked the guys to look into this for you. At this point they have checked the calibration on the probe used on your sample and said it was fine. What they are doing now is checking on the interferences involved with hobbyist titration kits and comparing them with the interferences in our probe + program method in hopes that it will illuminate a reason for the difference. It may be that the presence of magnesium carbonate may shift one test up and one down for example so they will look into it. I will let you know as soon as I do what they come up with and we'll figure out where to go from there!

Thank you for your patience and we appreciate your time addressing this concern.

Jeremy Redmond
AquariumWaterTesting.com

 

[Goodwin9]

I wrote to AWT and asked about the difference in the CA test results and thought that I would post the reply I received back from AWT.

Hello Chuck,

Thank you for writing. I know that the calcium test uses an ion-selective probe and I have asked the guys to look into this for you. At this point they have checked the calibration on the probe used on your sample and said it was fine. What they are doing now is checking on the interferences involved with hobbyist titration kits and comparing them with the interferences in our probe + program method in hopes that it will illuminate a reason for the difference. It may be that the presence of magnesium carbonate may shift one test up and one down for example so they will look into it. I will let you know as soon as I do what they come up with and we'll figure out where to go from there!

Thank you for your patience and we appreciate your time addressing this concern.

Jeremy Redmond
AquariumWaterTesting.com

 

[USC-fan]

<a href=showthread.php?s=&postid=11005309#post11005309 target=_blank>Originally posted</a> by Goodwin9
The report I got from AWT was sent to me in a PDF format, I printed the report and scanned the first page so that I would be able to post on the forum. If you send me your email, I will send you the complete report as sent to me by AWT.

Oh they must have just change there format.

When i send my next monthly test i will test that water with my Nutrafin kits.

 

[Goodwin9]

<a href=showthread.php?s=&postid=11007997#post11007997 target=_blank>Originally posted</a> by USC-fan
Oh they must have just change there format.

When i send my next monthly test i will test that water with my Nutrafin kits.

I checked a few prior to sending off my samples, CA was the one that wan't even close to what I had tested.

 

[bertoni]

Someone might want to ask them how they treat the Ca sample. Calcium carbonate can precipitate out of the water and not show up on a calcium test. Alkalinity tests might or might not be similarly affected, depending on how the samples are handled.

 

[USC-fan]

check out this thread, he tested the water he sent in.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1227423

Salifert test results
Ammonia (NH3-4) 0
Nitrite (NO2) 0
Nitrate (NO3) 0
Phosphate (PO4) 0
Silica (Sio2-3) No Test
Potassium (K) No Test
Calcium (Ca) 390
Boron (B) No Test
Molybdenum (Mo) No Test
Strontium (Sr) No Test
Magnesium (Mg) No Test
Iodine (I) No Test
Copper (Cu++) No Test
Alkalinity (dkh) 2.4 meg/L

AWT results

Ammonia (NH3-4) 0.003 Good
Nitrite (NO2) 0.004 Good
Nitrate (NO3) 0.4 Good
Phosphate (PO4) 0.23 Good
Silica (SiO2-3) 2.4 High
Potassium (K) 365 Good
Calcium (Ca) 452 High
Boron (B) 3.9 Good
Molybdenum (Mo) 0.2 High
Strontium (Sr) 9.7 Good
Magnesium (Mg) 1131 Good
Iodine (I¯) 0.01 Low
Copper (Cu++) 0.03 Good
Alkalinity (meq/L) 2.01 Low

 

[Goodwin9]

<a href=showthread.php?s=&postid=11040633#post11040633 target=_blank>Originally posted</a> by USC-fan
check out this thread, he tested the water he sent in.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1227423

Interesting......I am expecting results back from one of my other tanks today or tomorrow. Since the water in that tank was made up using the same RO water, I am expecting copper & silica to be on the high side again. I will be interested in seeing how the CA comes out in this test. I tested the tank prior to sending off the sample and CA read 420......

 

[USC-fan]

cool, keep us updated!

 

[einsteins]

I also tested my water sample before sending it in

Potassium
Zeo kit=340
AWT=338

Calcium Tested
API=420
Salifert =410
AWT=379

Phosphate
API=0
Salifert=0
AWT=.60

Magnesium
Salifert=1300
AWT=1387

Alk
API=8.2dkh or 2.9meq/l
AWT=2.96meq/l

Thats how my test kits faired against AWT.

Thought you might want to know....

einsteins

 

[jmait769]

Chuck, my results are opposite of yours (link by USC-fan)!

Using the Salifert Ca (7 months old) kit I was reading low at 390 and dosing accordingly. I have been dosing like crazy and it never increased. I’m going to order a LaMotte Ca kit and test with that since it is now, according to the AWT test, high.

I will let you know as soon as I do what they come up with and we'll figure out where to go from there!

Curious to see what your new results are and the AWT reply.

Using the Salifert Alk test kit (7 months old) I was always reading 2.8 meg/L and dosed accordingly. I got a new Salifert Alk test kit after reading on RC some were having incorrect testing results and it read low at 2.4 meg/L. I ordered a LaMotte Alk also and it tested the same as the new Salifert test kit so I increased Alk based on that.


Jay