LFS water testing contradicting.

[Miami Reef]

Same day; Same sample of water, different LFS. I tested my water at 2 different LFS’s and their results contradicted each other. The parameters in question are Cal and PH. The 1st store said my Calcium was too high Cal: 490 and my PH Ph 7.8 was too low. He also said ALK was fine. I was dumbfounded because I did a water change 2 days ago.

The second LFS (the ones always go to) said my Calcium was too low (380) my alk was too high, and my PH was fine.

I’m really confused. I kinda trust my current LFS because they tested the water in front of me and I was the color card matching with the color of the test tube. I’m not making any changes because I don’t know who to believe.

 

[Crabs McJones]

Did both stores use the same brand test kit?

 

[Randy Holmes-Farley Verified Community Expert]

There are tons of mismeasurements in the hobby, and lfs tests are no different.

 

[Miami Reef]

I have no clue what brand test kits either of them used. They both made a scary claim with the Calcium. One was too high and one was too low. I don’t know which way to adjust it to. All I know is that the coralline algae growth is not spreading the way I want it to. The LPS look fine though.

 

[Cory]

Whats a new batch of salt test at 35ppt?

 

[Randy Holmes-Farley Verified Community Expert]

Actually, the 490 ppm calcium is fine and 380 is borderline fine too.

 

[Randy Holmes-Farley Verified Community Expert]

I’d get a Salifert kit and test it yourself if you are concerned.