Stability of Sodium Metabisulfite
Posted: Sat Apr 08, 2017 8:36 am
During my attempt at filtering I've noticed some obscure issues with my quantity of SMB on hand when using it to remove O2 from a mixture of starstan.
In multiple experiments I required almost 4 grams of SMB to reduce the O2 from approximately ~7ppm O2 in a litre of water. Whereas previously I'd only used a fraction of that quantity for the same effect. I ran some side by side experiments with newly purchased SMB vs my old SMB and the new SMB performed as expected, however the older SMB had variation - some worked as described and some didn't (from the same container). This was with tap water, RO water and starsan/tapwater mix.
I believe the SMB I have stored has deteriorated and isn't scavenging O2 as it should be, proven with an O2 meter. There is some smaller clumps in the container (plastic with screw lid) and it's a bit over 6 months old.
Has anyone experienced anything like this? This potentially could impact many of you if what I've observed is replicated elsewhere.
In multiple experiments I required almost 4 grams of SMB to reduce the O2 from approximately ~7ppm O2 in a litre of water. Whereas previously I'd only used a fraction of that quantity for the same effect. I ran some side by side experiments with newly purchased SMB vs my old SMB and the new SMB performed as expected, however the older SMB had variation - some worked as described and some didn't (from the same container). This was with tap water, RO water and starsan/tapwater mix.
I believe the SMB I have stored has deteriorated and isn't scavenging O2 as it should be, proven with an O2 meter. There is some smaller clumps in the container (plastic with screw lid) and it's a bit over 6 months old.
Has anyone experienced anything like this? This potentially could impact many of you if what I've observed is replicated elsewhere.