Stable tank is recommended for any anemone, but if your water levels are ok it should be fine. I had a 46 gallon that I added a BTA after 4 months and he did amazing, I just transferred him to a 112 gallon that has only been running for about a month, but he is doing just fine in there as well. You just have to stay on top of your water parameters. Make sure to use RODI
when setting up, make sure your salt and temp is always consistent. After a couple weeks check to make sure PH and other parameters are good, and if so, your BTA will be just fine. Contrary to what people think or say, BTA are very adaptive and tough. Hope this helps.