HANNAH-API-RED SEA weird results!!

[jordimex]

So today a couple friends came to my house and are really knowledgeable about both marine and fresh water tanks, they are from argentina and brazil they came to the house for a beer and to talk about corals and fish,
one of the guys told me that he wanted to test my water so i handed him all my test kits
he did 3 red sea calcium tests and got a result saying my calcium was under 290
i did 1 api test and got a result of 380
i did 2 test with my Hannah checker and got 1 result of 511 and another one for 490
he did the test down to a T same as me how are this results posible!! and which one should i trust
tomorrow ill be getting a salifert test to see what it says

any advice?

 

[lou dog420]

I have the Hanna calcium checker and I have always thought that it reads high.

 

[jason2459]

Average them out and you're set.

Reagents do go bad or come bad. Happens with all kits. The red sea is either bad or not done right. I found API kit to be reliable and accurate enough. I don't have any experience with thr hanna but others seem to have had troubles with that one.

 

[jason2459]

Oh and a difference between 511 and 490 is negligible and to me the same number and nice to see.

 

[Martin Kuhn]

Average them out and you're set.

I don't agree. Results are strongly different.

Without having measured a sample with EXACTLY KNOWN Ca concentration, you can't which test kits measures correct or how far it is off.

I suggest to buy a Ca-reference or, better, a salt water multi reference and measure with all test kits. Then you know.

 

[jason2459]

It was sarcasm as the next statement was in belief that the redsea reading is inaccurate. Otherwise I would have no issue with averaging the API and hanna numbers. Both strike an acceptable range.

 

[GoVols]

Lol!!!

I'd trust the API over the hanna cal for a ball part #.
Got in my first bad refill on the Red Red Pro cal ever, at the first of the year.

 

[GoVols]

I found API kit to be reliable and accurate enough.

+1
And a good cross check kit...

 

[Tautog]

Interesting, but did you test for KH???
Ca tests do vary during the day because of consumption

 

[jordimex]

all of the KH test came in the ballpark hanna 8.1 red sea 8.2 and API 8

 

[jordimex]

Lol!!!

I'd trust the API over the hanna cal for a ball part #.
Got in my first bad refill on the Red Red Pro cal ever, at the first of the year.

i am thinking i have a bad red sea reagent or something it was the first time buying that product don't think i will ever do it again

 

[jordimex]

I don't agree. Results are strongly different.

Without having measured a sample with EXACTLY KNOWN Ca concentration, you can't which test kits measures correct or how far it is off.

I suggest to buy a Ca-reference or, better, a salt water multi reference and measure with all test kits. Then you know.

i will try to get salt water multi reference to see make sure

 

[Martin Kuhn]

Again.... without having a proof by a trusted sample that is measured, all assumptions which test kit might be the most accurate is nonsense in my eyes

 

[jason2459]

A good reference solution can be handy and can be made. But luckily the margin of an acceptable value for our tanks is rather large.

 

[GoVols]

i am thinking i have a bad red sea reagent or something it was the first time buying that product don't think i will ever do it again

Could be
Been using the Salifert over here.

 

[jordimex]

hey @Randy Holmes-Farley could there be another explanation apart from the test reagents gone bad?

 

[Martin Kuhn]

I'm not randy
But
Another reason might be that you didn't act fully as the testing method including reading the measurement results, was intended

... all test kits work a but differently

 

[madweazl]

Interesting, but did you test for KH???
Ca tests do vary during the day because of consumption

Eh?

 

[Randy Holmes-Farley Verified Community Expert]

hey @Randy Holmes-Farley could there be another explanation apart from the test reagents gone bad?

User error.

I've done lots of tests, leaving out a step. Some people read syringes backwards or incorrectly, misremember volumes to use, cross contaminate equipment, etc. All sorts of things.

The 290 ppm sounds off, regardless of the method. It is very rare for a reef tank to get that low.

 

[Tautog]

Eh?

Alkalinity???
It's a test that is really the most important, and should be done more often that most. If you want stability chase Alkalinity, then Ca and Mg in that order. All 3 work together