U/V globes are consumable items. Over time the filament in the unit degrades and although they still appear to be working the amount of effective U/V they emit can be almost zero. A typical life of a U/V glove will vary from between 6 to 12 months. If your pond water is going green it’s time to change the globe!
When shipping these globes we protectively put them into PVC pipe to ensure they don’t arrive broken at your side.