Hibiscus do best as rotational plants, but in my opinion to give a hibiscus enough time with just uvb lights for chameleons and natural sunlight you need around 3-5. However if you get a good grow light system, which often can be provided by using a quad system bought from light you reptiles. And filling it with a high quality arcadia uvb light, two different spectrum plant grow lights and then filling the last one with whatever you think is best or what Todd recommends. Often in order to produce consistent blossoms without natural sunlight a plant needs a specific spectrum of lighting.