Test kit differences

[TheRealChrisBrown]

I have been using Salifert tests for some time now to check my Magnesium and Alkalinity, and a Hanna checker to check Calcium. I went to order more of the mag and alk tests when I was lured into buying the Red Sea Reef Foundations Pro test kit, basically because for the same price of 2 Salifert kits I got all 3 (Ca, Alk, Mg). I also knew that I could enter test results from Red Sea into the Apex, so I liked that.

I've tested twice using the Red Sea kit and the remaining Salifert kits and side by side the results are wildly different. Who do I believe? The Red Sea tests are all low compared to Salifert and Hanna. For example Hanna checker shows calcium at 470, Red Sea shows it at 395. Second test a week later, Hanna shows 458...Red Sea is 365. They both show a trending loss in Calcium, but are pretty far off of each other. The Alk results between the Red Sea and Slaifert have been the closest yesterday one measured 7.2 dkh and the Red Sea was 7.0 dkh. Mg Salifert showed 1180, Red Sea was 1020.

All kits expire in 2017, and I checked the Red Sea recall and none of the batch #'s o my kits were in the recall.

Ideas, suggestions? I don't want to start correcting based on the Red Sea numbers...only to find out that I pushed my Calcium up to like 700 or something.

 

[sethsolomon]

average the 2?


Also double check the results to make sure you are using the test right.

 

[zombie]

One thing to remember with the red sea that might explain your low readings. When you do the titration, do not stop when the color starts to change. Continue shaking and the color will change back. Only stop when the color stays changed after shaking.

 

[TheRealChrisBrown]

I just found this article that sort of sums up what I'm thinking:

http://www.advancedaquarist.com/2012/6/chemistry

 

[neil82]

I just found this article that sort of sums up what I'm thinking:

http://www.advancedaquarist.com/2012/6/chemistry

That is a good article. I have the red sea reef foundations kit too. I struggle with the alk test the most. It's tough to tell exactly what color is the end color. Not sure if other titration kits are like this the red sea kit is the only one I have tried so far. I often end up repeating a test several times and average the results.

 

[bathomassr]

Be sure to view red sea test videos on YouTube. I found out I was doing the alk test wrong but was right on with cal and mag. Videos are very good.

 

[TheRealChrisBrown]

Be sure to view red sea test videos on YouTube. I found out I was doing the alk test wrong but was right on with cal and mag. Videos are very good.

Thank you for the recommendation! Their videos are very good, I don't see any differences between what he does and what I do....but it is good to see the tests performed as the company wants them performed.

CA - https://www.youtube.com/watch?v=VT9tEHp828w
MG - https://www.youtube.com/watch?v=MofaqM-I6uM
ALK - https://www.youtube.com/watch?v=bb4NnYOFneA

 

[SynDen]

That is a good article. I have the red sea reef foundations kit too. I struggle with the alk test the most. It's tough to tell exactly what color is the end color. Not sure if other titration kits are like this the red sea kit is the only one I have tried so far. I often end up repeating a test several times and average the results.

+1 the alk test in particular is very hard to tell. The mag and calc tests however are pretty easy, but the alk is very hard to tell when it reaches the desired color, and to make it harder the color varys from batch to batch.

 

[bathomassr]

+1 the alk test in particular is very hard to tell. The mag and calc tests however are pretty easy, but the alk is very hard to tell when it reaches the desired color, and to make it harder the color varys from batch to batch.

THAT explains a LOT! I wondered why my colors were slightly different than what I was seeing on the video. Thanks Angel.

 

[zombie]

With the Alk test in particular, I have noticed that in all cases, (comparing results to other test kits and had a friend do a legit test to compare in mines Chem lab) is that you need to go until the color completely changes (purple shows low, keep going until you just barely hit blue)

 

[SynDen]

Ya except it doesnt turn purple any more. It turns this very light orange color now and it is very difficult to see where it finally stops changing color. With the calc and mag tests it is very distinctive, as the colors will transition to an in between color and then will very noticeably change to the final color but not so with the ALK test any more.

 

[zombie]

That's new. I'm still using up all my tests that turn purple then blue.