Ok to mix Epsom salt and Bt?

Just making sure. Are there any concerns with mixing Epsom salt with a couple drops of BT in the same mix? It occurred to me that the Epsom might negatively affect the Bt culture, though hopefully that’s not the case. Any insight appreciated. The Bt is simply preventative at this point, though I suspect the gnats will return without it.

Don’t know the answer, but if it was me, I’d put them on one at a time, with a week or so between them.

It doesn't matter.
I've added BTi to my reservoir and it still worked as expected.