planted tank ...

I just switched over my fish from my 10 gallon to my 29/30 gallon. While in the 10 gallon the plants I had looked nice and I considered the tank fairly heavily planted ... the fish seemed to like it too. So, now that the plants are in the 29/30 gallon they look very thin and spread out. I know I will probably need more but my question right now is planting them in the gravel. How deep do you all (those who have live plants) put them in the gravel? Also, I was thinking of switching from gravel to sand ... or maybe half and half like I had in the 10 gallon. What do you guys recommend?
 
You may want to post questions in the plants forum as well.
How deeply the plants are placed in the substrate depends; are these stem plants? If they are, I don't think the exact depth is crucial - as long as there is at least one leaf node (with leaves removed) beneath the substrate, the plant will form roots. AFAIK, rosette plants can suffer if they're pushed down too far - the 'crown' that the leaves grow from should show a little above the substrate.
If your plants have enough light, nutrients and CO2, they'll grow taller and/or spread out, and the tank will fill out; you won't need to buy more plants (unless you want other kinds ;)).
If you're considering changing substrates, you may want to read about those designed specifically with plants in mind - Eco-Complete, Flourite, etc.
 
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