Brute trash can issue?

I use three Gray Brute trash cans for my reef maintenance; ro storage, salt mixing and kalk topoff. Something is happening to the topoff trash can for my 125 when I add kalk, after about two days I begin to get an odd chemical type smell that is quite powerful. I get the same smell in my other bucket if I let my salt water sit for a couple of days. I never get a smell in my ro trash can and it is always full of water (I think that eliminates my ro components as a possible cause). I don't get the same smell from my topoff Home Depot bucket that also has kalk for my 29. I never had this issue before because I only mix salt for a few hours, it never sits for long. Now that I am using kalk in my 125 I've noticed the smell.

The aha moment I had was when I left some salt water in my mixing trash can for a few days a month ago and got the same smell. I actually threw the water away and didn't give it much thought because it was the only time that it had happened. I made the connection when I recently started to use kalk in the same type of trash can and smelled it again.

My concern is that the three acros I put in the 125 are not showing the same strong polyp extension as they have had in the 29, granted it's only been a few days but I would expect better pe. I changed my carbon so that should remove any chemical residue if there is any. I also have had a large ball of chaeto die over the past week or so, I believe that is related to lack of nutrients or wrong/too strong Home Depot led flood light that I've been using.


Any thoughts?