Is this salt burn or something else?

[lelani]

I have been an orchid owner for about 8 months or so now. When winter came along (first winter with my orchids) I started noticing the roots getting brown/dark patches and sometimes it even looks quite dry. Preliminary research tells me that what is happening is salt burn but I'm not entirely sure. I water every 1-1.5 weeks, use slow release fertilizer, and flush once a month.

In general, I don't know if what's happening to the roots is actually affecting my orchids as I'm still getting root growth and blooms but if it is something that can affect them over time then I'd like to get a handle on it now. Not to mention, it is not very attractive looking as prior to this the roots were plump and green with no blemishes and I loved it!

Would anyone be able to provide any insight or advice on what this is and what can be done?