Orchid fertilizer/supplements question

[Ray]

SuperThrive is a mixture of synthetic hormones, vitamins, and who-knows-what-else.

Mega Thrive is a urea fertilizer to which large doses of boron and molybdenum have been added.

The former may stimulate root growth (if it is fresh). The latter stimulates the plant into producing the hormones that stimulate root growth, and is far more reliable in doing so, although it makes the plants toxic to birds and mammals.