I'm ordering some 24" 20W bulbs from bigal's and I need some advice. They have TropicSun 5500K bulbs for only $4.49 each, FloraSun 8500K bulbs for $7.99 each, and UltraSun 6500K bulbs for $10.49 each. Money is important here which is why I'm naming these cheaper bulbs as opposed to some $20 ones. Is there any reason I should get another bulb over the TropicSuns? According to ZooMed's website the FloraSun bulbs have greater intensities in the blue and red zones for better plant growth. Is this important or just marketing hype?