test restults are way off help me understand

can someone please tell me whats going on? I use Instant ocean salt and have been using it for years. recently purchased a red sea ca, mg and alk test kit which has been testing high results in my tank whihc I will post below. i also tested a freshly mixed batch of water and tested that and will post below as well...

ok here are the test results for mt main tank water:

ca 490 salifert
alk 10.5 dkh red sea
mg 1590 salifert
po4 .27 hanna reactor
no3 15 APT
ammonia 0 APT
sal 34.9 probe
ph 8.06 probe
temp 80.4 probe
orp 316 probe


ok here are the results on a freshly mixed Instant Ocean saltwater;

Tropic marin Alk = 6 dkh
Red sea Alk = 9.1 dkh

Red sea Calcium = 550
Salifert Calcium = 450

Red sea Mg = 2100 (woa)
salifert Mg = 1650

so based on these results I believe a few things are happening...

1. there is something up with the red sea test kit as they all show high results
2. Instant ocean as i suspected and tested in the past shows very high Mg , spot on Ca and slightly low Alk if you only look at saliferts and tropic marin results and you ignore red sea.

anyone have any idea whats going on? is my suspition correct that the test kit is bad? I've know that levels with IO could be a little high in mg and low on alk but the results with the red sea is out there.

 

I think you are right on the test kit being bad.

 

I use the RedSea Pro with great results. The RedSea is a little tricky at first but once gotten used to I've found it to be very accurate. Make sure that your reading how much titrator is used and not what's left

 

the test kit is definatly bad... I agree. there is no way that I'm reading the numbers wrong. I am reading what was used for sure. In fact for the result that I got at 2100 mg. I had to refil the syringe a second time befor the color even showed signs of changing... so I added to what was used and it was off thier chart provided.

 

Dang it this info sucks!!! Another with a bad Red Sea kit, grrrrr. I'm counting my blessings then as I got a good kit. But now I'm wondering just how accurate they are in the long run.

 

I would take your water to your LFS and have them test it. Take the results and test kit that you think are the most accurate and run with it. As it was explained to me...most test kits designed for home use are not accurate. Take the "lie" that you are most comfortable with and use it as the basis for your actions.

 

I just bought the red sea reef foundation test kit and wanted to see if i got different results from my salifert test kits.
Results:Salifert
KH-10.5
Mag-1410
Ca-440
Results:Red Sea
Kh-10.6
Mag-1440
Ca-445
I did find it kind hard not to revert back to using saliferts reading of the reagent which the first time gave me crazy results.I would test again and make sure to follow the directions step by step.

 

hey thanks for taking the time to run the comparitive tests and from what I can see they are very close so I would say that both of your kits are fine. I'm sure this is a rare case of bad kit. from everything that I've read about red sea test kits have been very positive. I'll post my new results once the new test kit from red sea arrives.

 

after getting a replacement test kit from red sea and that one also reading very very high results I will not use their products. I tested thier results against three other test kits. I'm going back to salifert.

 

I encountered a bad Red Sea kit for Calcium once. It would read 400 no matter which tank I tested.Very weird.