When to use UV light?

[koi808]

I have a 750 gallon pond in almost direct sunlight. I have a shade canopy to cover most of it providing shade to the fish/water. I'm using a 25W UV light. I noticed that when I turn it off, the water quality (clarity) doesn't really change. Since I'm not having any algae issues with the light being off, is there any other benefit in having it on?

[two_wheeled]

Nope! If your water is clear and you don't have green algae, you don't need to leave the UV light on.

[BAVOTOI]

Just leave UV light on. It's don't hurt anythings.

[Grumpy]

I only turn on my UV when/if green water appears, usually in early spring. The UV bulbs only have a limited operational life to kill algae (they will emit light longer, but not sufficient UV), so I keep mine off until they are needed.

[BAVOTOI]

Hey bro my koi eat algae in winter. My UV's on just control green water.