I would go for Amazon frogbit
Abt. your shrimp deaths I have a few question n a bit of advice may be after this your problem will be solved.
Atleast you will find the root cause to yr shimps dying.
Your tank is 10 gallons right?
Please specify your substrate, cycle period, RO/tap water, what ar yr water parameters i.e. PH KH GH if possible TDS
What is yr tank temperature? Is it steady ?
Do u have a heater ?
You change water weekly .
What kind of De chlorinator do u use if u use tap water?
Do u use any kind of mineralizator or liquid to help yr shrimps moult?
Do u keep fish along with your shrimps ?
Coz shrimps r stressed by fish also they need cleaner water so better separate them.
Did u buy yr shrimps from a pet shop, online ship or hobbyist ?
Did u check or ask for water parameters from where they came?
I think if try to anwer all my questions you will find an answer to yr problem.
Really hope for you that yr shrimps stop dying n start breeding
Most imp.you start enjoying the hobby.