• EricW76 commented on radarguy's instructable How to make a flow switch9 months ago
    How to make a flow switch

    This is an inventive design. But, turning off a UV lamp and back on will have two problems. One - bulb life is negatively impacted by number of power cycles. Two - and this is much more important - the UV bulb takes significant time to "warm up" when first turned on in order to provide adequate intensity to sterilize the water. The light wavelengths that actually sterilize bacteria is ultraviolet (you cannot see it with the naked eye). For the bulb to provide the necessary intensity, it can take several minutes to warm, depending on the bulb, and the age of the bulb. "Glowing" does not equal UV light. During that time, bacteria laden water will be flowing through your system and into your water system. This is why fluorescent UV systems typically are constant on. There are LED technologies that are coming that will offer that instant on ability you would need to safely do this. But cycling the bulb in fact does not provide safe water, and is not recommended.

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