NONE...You don't need nor want to put ANY type of artificial lighting over a parrot. Period. There are a multitude of reasons why not, everything from they don't need it if they are being fed a healthy, varied, low-fat, high-protein diet, to the fact that somewhere around 95% of the lights that are sold for pet birds/parrots are not only inadequate and do nothing at all to help them, but actually often hurt them, causing Eye damage and Photoconjunctivitis, Blindness, Skin burns/damage, Skin Cancers (Squamous Cell and Melanoma), etc. (as well as many sold for Reptiles who DO NEED an artifical UVB light)...Unless you know a lot about UVB light strengths, intensitys, and especially types and types of fixtures, then don't risk it...And don't waste your money, it's totally unnecessary and chances are you will only regret it in the end. And this goes for all UVB lights, "Full-Spectrum" lights (that's a misnomer), etc.
There is nothing better for any and all pets and people than some NATURAL Fresh-Air and Sunshine, at least once in a while. Since UVB light from the Sun cannot at all penetrate any type of clear-plastic or glass (100% of UVB is blocked by all windows), nor penetrate any types of mesh windows/window-screens either (unless the holes in the screen are HUGE), that means putting your bird inside of a window in your home or on a Sun-Porch that is closed-in by mesh, clear-plastic, etc., that means that if you are concerned about getting your bird some Fresh Air and Sunshine, that's exactly what you should do...Either inside of a cage, a carrier, or on an Aviator Harness, take them outside (supervised) whenever you can for an hour or two. I take my guys all out on their Aviator Harnesses, and sometimes when I have one out on their Aviator Harness I'll put the others inside of a huge Flight-Cage I have in my garage, and push it out into the yard/driveway, and I'll sit there with them for an hour or two and let them just play in the sun (making sure they can get into a bit of shade if they want to, and that they always have water, and I never walk away and leave them unsupervised, so do it during times when you are totally free and don't have other committments)...That's the best, safest way to get your bird some Sun...Artificial UVB and Full-Spectrum bird-lights are just asking for serious issues for your bird's health with no benefits at all in-return...
