red sea vs salifert ALK testing

[M4sonic]

My salifert test was running out so i bought a red sea alkalinity pro test.

Now I'm getting different results from both test.
salifert: 9.6dkh
red sea: 8.4dkh

I'm not sure which one to trust.
the red sea is harder to read the green color change,but even if i go into the overdose color change (yellow) the measurement is still lower than the 9.6dkh salifert gives me.
Both test are well within their expiration date, and so far ive done each test about 5 times and the test is consistently off each time.
I dont really care about a 0.2-0.4 dkh difference but 1.2 dkh off is to much for comfort.

 

[PatW]

Salifert always seems to come out about ,6 to 1.2 DKH higher than Red Sea Pro for me. These tests do not meant to give really good absolute results. They are better for giving you a ball park notion of DKH. They are more valuable in letting you know if the ALK is rising, falling or being stable so you can dial in your dosing.

 

[fr3n0z]

i had same doubt. Got salifert, tropic marin and jbl and while tropic marin and jbl where within a 0.5dkh difference salifert was 1.5dkh higher. and i was reading it at lavender color, not pink. Everyone speaks well of salifert but i'm not convinced.

 

[Spare time]

I'd just pick one and stick with it

 

[M4sonic]

well if the salifert is reading 1.2 dkh to high that would mean ive been running my tank at 6.3ish

which could explain why my corals started doing better when i decided to up my alk to 9 (which would be 7.8 assuming the same 1.2 dkh error)