pH range and TDS limits

[Ross]

I have used MSU mix for RO water (mixed in RO water, of course) with every watering. I have rarely flushed the pots. I use barks mixes, mainly. I do not use this regimen with Masdies, but with every other orchid, I do use it. I have seen tremendous response as I have posted many times in the past. Both with roots and leaves. Often with flowering as well. But then, I flush the pot with the fertilizer mix as I water (or submerge the mounts). So maybe this sort of flushes the old buildup?