Like all phrags, this likes to sit in a pan of water, and receive moderate light. Phrags do tend to grow like weeds, given ample water.
This is a primary hybrid of schlimii and longifolium. As such, the flowers can vary, sometimes significantly from one plant to another. Lots of water — it prefers to sit in it without going dry for any length of time. Moderate light (sunny windowsill is fine) or semi-shade if outdoors or in a greenhouse for the summer.