[HELP] test kits are confusing me!

[CamDAX]

So I've never dosed Mg in my tank the bottle of the stuff I have is still sealed to prove it. I use Red sea coral pro salt and I just tested the tank with two kits, salifert tested 1470 possibly 1500 (the end of the table) and red sea tested 1400. These readings make no sense especially since red sea salt should mix mg at 1.025 to 1360-1420ppm.

I'm trying to figure this out since my corals, as well as coralline algae aren't growing as fast as they used to and I want to understand my test kits.

 

[linkedsilas]

I think it all depends on the test kit itself and the company. Some are better than others in reading certain things. Can you go to your LFS and see if they have the same brand and compare? Sometimes kits get bad and can be useless. This is what I have found out when using kits in my job

 

[lmforbis]

I am having trouble understanding the issue.
The difference between the test results is with in 5% of each other. That is not an unacceptable difference between any tests made by different manufacturers. The difference is not significant nor is it out of line with what you would expect from your salt.
You have to remember these are hobby grade test kits.

 

[CamDAX]

I feel like the levels are lower than they are testing as because my coral used to look like the first photo from 2014 and now they look like the second from now (2016). They lost their blue tips. The levels then were CA 435ppm ALK 4.1meq/L MG 1390ppm now they are CA 490ppm ALK 201ppm 4.02meq/L MG 1840ppm.

When I get the chance I am going to go verify my readings with a LFS.

[Edit:] just noticed that I got a lower flow powerhead are removed my old powerhead because I thought it was too much flow for other corals. Do you all think this may be the cause?