I think this is an interesting topic - DSM vs normal start-up.
Tropica and most other nurseries grow almost all of their plants emerged (except the 100% aquatics like Vallisneria). They're grown in 'perfect' conditions this way with unlimited access to CO2, huge amounts of light (daylight is far brighter than aquarium lighting), and their nutrient management is amazing.
Growing plants this way allows them to build-up massive nutrient reserves and strengthens them considerably - from both a physical sense and adaptability perspective. Similar principles apply to their 1-2-Grow range - and these are actually better at adapting than regular emergent growing in the nurseries.
So these plants are really strong, really healthy and full of nourishment when we buy them fresh.
Then we stick them in our tanks - let's say using DSM.
Not so good. The lighting is poorer, nutrients control won't be as effective, and generally the plants will have a harder time at adapting to another emergent environment.
I think it is better to grow these plants right away underwater as soon as possible. This is the way they're designed to be used, and why companies like Tropica have invested so much into making the plants as healthy and strong as possible, allowing them to easily adapt to the wide variety of underwater environments that we, the hobbyists, keep in our aquariums.
Plant melt will be almost non-existent when going straight into underwater growth (submerged) if you use healthy plants from the start-off, and this is where 1-2-Grow and other lab cultured plants come into their own. Obviously your growing conditions (lighting, CO2, nutrients, circulation) need to be appropriate for success. With DSM getting these factors correct during the flooding and transition phase is even more essential.
I think the only time I'd ever bother with DSM again is to grow moss using the blender/yoghurt method.
Ian - sorry for the tangent mate! Good luck with the UG and I love your professional use of Microsoft Paint!! lol
