I have 2 VHO bulb came with a tek light fixture that was previously used on a SW tank from the seller. The marking was gone, so I can't see what kelvin temp (Seller didn't remember either). It looks like pink color bulb after turning it on. Are these bulb useful for planted tank? I seemed to get some black hair algae growing on the leaves after using for a couple weeks. Will higher kelvin bulb cause algae problem anything more than 10000K?