plants in main tank

[cdi919]

i have a 20 extra high and want to put turtle grass and shoal grass and a mangrove. my first question is will a power compact with 2 6500k bulb be enough light?
my second question is does the mangrove have to stick out or the water or can it be planted in the sand even if the leaves are in water?
my third question is how many plants can i add and which kind?

 

[billsreef]

Is that 20 extra high the one that looks like two 10's stacked one on top of the other? If so it might be too deep for the PC's to punch enough light to the bottom for turlte grass. Some types of shoal grasses such as Ruppia maritima would do ok though. The mangrove needs to grow up and out of the water, so they are best done in tanks lit by raised pendants.