Alk Test per 3 kits

[andys]

Hello all


Chasing the Alk reading. i decided to try 3 different kits. Red Sea, Salifert, Hanna.

All were different. Test are conducted on 3 tanks

Red Sea Salifert Hanna
little 9.0 7.7 8.6

Big 8.5 7.0 8.2

Frag 7.0 8.6 6.7

what the heck. which one is correct ?

Andy

 

[alyee5]

Can you test some fresh saltwater mix at a measured salinity and compare those readings vs the manufacturer's numbers?
At least the deltas between the Red Sea and Hanna are about the same between each tank...that Salifert measurement on the frag is out of whack...
I am still new to the coral thing, so I can't comment on how much a 0.3 delta (Red Sea vs Hanna) makes on coral health...I think as long as there in consistency in the readings that is the goal...

 

[skim]

I would be more inclined to go with the Salifert, there also should be a standard/base solution to test and see if the kit is OK.

 

[andys]

Here is the test with fresh salt water made this morning. Red sea coral pro

Red Sea Salifert Hanna

12.3 3.8 10.9

 

[Bdog4u2]

Pick a test and stick with it since stability is more important than a certain number as long as it's in the correct range

 

[andys]

Well bdog4u2 I don't wanna use a test kit that reads very low or high. It needs to be close and from what I can tell the Salifert kit is way off. Stability at 3.8 isn't gong to cut it

 

[skim]

Like I said Salifert should have a Base solution test in the kit, it will tell you know if the kit is working properly.

 

[Bdog4u2]

If you tested a fresh mix and got 3.8 something isn't right with the test. me personally I've never got that low of a alk reading from fresh salt mix. I've got very high readings back when I used tropic marin pro salt mix. all the test kits in this hobby are hobby grade and aren't the most accurate tests. you can send it to a lab then you'll know which is correct

 

[alyee5]

Here is the test with fresh salt water made this morning. Red sea coral pro

Red Sea Salifert Hanna

12.3 3.8 10.9

Yeah, sounds like a bad Salifert test kit/reagent. I started to use RedSea Coral Pro and I measured the same Alk u did at 1.026. I should try testing with my Red Sea kit to see if it reads in the 12 range like yours.

 

[ksc]

Well bdog4u2 I don't wanna use a test kit that reads very low or high. It needs to be close and from what I can tell the Salifert kit is way off. Stability at 3.8 isn't gong to cut it

You could always get some NSW from the bay and check your kits. It should read about 7 dkh. I wouldn't trust those standard solutions, They are supplied by the same companies that can't make accurate test kits...

 

[andys]

Like I said Salifert should have a Base solution test in the kit, it will tell you know if the kit is working properly.

I have never seen a base solution come with a test kit. And NO the Salifert kit did not come with one

 

[Randy Holmes-Farley Verified Community Expert]

what the heck. which one is correct ?

Andy

Maybe not any of them. They all can be pretty good, but can suffer from user errors, old age, etc. That's why I prefer a DIY using a commercial standardized acid solution and a pH meter. Harder to mess up since you are using a bigger volume, and cheaper in the long run too, assuming you have a pH meter already.

A DIY Alkalinity Test: By Randy Holmes-Farley
http://www.reefedition.com/a-diy-alkalinity-test-by-randy-holmes-farley/

 

[mermaid62]

I have had similar problems with reading alkalinity kits. I have experimented with all three and have found Hanna to test low compared to the other two. I have chosen to stick with the Salifert as it is the easiest to us.

 

[andys]

Well I found the ISSUE. guess i should read the directions before i post. I was reading the syringe from the plunger down like the red sea. bone head move on my part

 

[Sabellafella]

Here is the test with fresh salt water made this morning. Red sea coral pro

Red Sea Salifert Hanna

12.3 3.8 10.9

3.8?

 

[Sabellafella]

Well I found the ISSUE. guess i should read the directions before i post. I was reading the syringe from the plunger down like the red sea. bone head move on my part

Lol it happens alot more often then you think. Salifert for me runs flush with both my hannah alk checkers. Redsea is about .6 dkh higher

 

[andys]

ya the red sea also is couple of digits higher also here