Whoever told you a T8 bulb is an upgrade is outright lying to you. Everyone who knows anything about lights will say the same thing. T-12 are the worst, T8 and fine for a kitchen, T5 are better and T5HO are best.
T12 vs T8 vs T5: "T-12"...As Outdated As Your Granparents Bingo Game?
For an anemone, you will require at least 6 x T5HO bulbs to get it to live. Or less expensive high quality LED
units (55 x 3Watt LED
). The sooner you take the anemone back to the store and raise a stink about their selling techniques, the more likely you are to get a refund. The longer you wait, the more likely they will say its your fault he died. He will die! Sorry. Just like you cannot live without water to drink, he cannot live without intense lighting.