Planting A Tank

[kojote]

i'm very much interested in acquiring a few live plants for my tank, but the plants i've had in the past didn't do well and slowly died. i suspect my water is too hard for the ones i had, water wisteria and red ludwigia. the water wisteria died within the first two weeks and finally today after about 2 months, so did the red. so i'm wondering, what plants do well in hard water? was it the water hardness or something else that killed them? do i need to take any special steps to care for plants? thank you in advance!
 
it is a 20 gallon tank with:
3 silver mollies
5 painted platys
& 1 mystery snail
 

 

[eaglesaquarium]

There are lots of factors, including the lighting and the duration of the lighting... more so than the hardness likely.
 
What are the dimensions of the tank?
What lighting are you using?
How many hours a day?
What's the substrate?
Are you dosing any fertilizer?

 

[jag51186]

I agree with eagle, plants actually prefer a little hardness to the water because they utilize the minerals. I would also suspect your lighting!