New to Orchids - bought vanda seedlings without realizing difficulties.

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You almost certainly don't have fusarium. Stop watching whatever channel suggested that to you. Fusarium does not manifest in Vandas with a red hue to the leaves. It manifests as roots suddenly shrinking down to threads even if humidity and watering are correct. People outside high-humidity climates don't need to worry about fusarium, especially in Vandas.

And stop pruning. Let leaves and roots alone until they turn brown and fall off on their own.