Does salt age? solving an alk/cal mystery

[jselzler1]

Hi,

For past 3 months my alk/cal readings have been consistent 8.2-ish dkh and 420 ppm, basically ever since I got ATO working w/ pure kalkwasser. I typically been testing every 2 weeks. I just recently did a test and alk was 7.2, cal 360, double checked with similar measurements. Prior test with the consistent values was 19 January. I haven't added any new coral to tank between 19 January to now. Consumption rate should be the same. ATO still sucking down 'normal' amount of kalkwasser. I mix the kalkwasser same as always. The only source of change since 19 January is two 10% water changes. I just happen to have some water mixed up now, tested alk and it was 5.4 dkh!! I used same Reef Pro test kit for alk/cal for all these tests.

This isn't a new bag of salt. I have been using this same bag for ~3 months also so won't say it is a bad bag. However, the last few batches of water uses salt from the bottom of the bag. Does the salt become stratified during shipping? Does salt possibly age loosing the trace elements? It was sealed, if memory is correct. Do test kits age? I could re-test with an API kit.

I learn new lesson to test salt mix. Oh, my current salt is Coralife. Should I change brands?

Thanks

 

[stingythingy45]

Is this Coralife salt a reef salt?
I would try something like Red Sea Pro or I.O. Reef Crystles or Tropic Marin.

 

[dlux5life]

It is typically suggested that you shake your salt containers to redistribute the alk and cal additives through out the salt mix. These additives can shift to the bottom or the top of the salt mix during shipping. So either shake the bag or shake the bucket prior to use and the issue may correct itself going forward.