Knowing the type of anemone you had makes a huge difference in terms of what we suggest you do -- some anemones like to attach their feet in deep crevices in the rockwork, while others like a deep sand bed. Then there are others that prefer smooth rocks.
The bigger picture is that is sounds like you need to get your tank husbandry in order before trying to house an anemone. For example, having a protein skimmer will probably help quite a bit. And measuring dKH is probably the most important thing to test, assuming your tank has been properly cycled.