Calculating Pond Evaporation: Is Floating Glass a Good Idea?

[peter2108]

I have a fish pond which may have a slight leak. Or not - maybe the water is just evaporating. Searching it seems there is not simple way to calculate how fast water will evaporate. So suppose I put a glass beside my pond and measure how far the level of water in the glass has fallen in - say - 24 hours. Say this is D mm. If it is only the surface area of the water that matters then presumably the pond should have fallen by D mm as well. Is this method likely to be successful?

@xts. Floating glass is a good idea - the po9nd is 3500 liters so its temperatuerew would vary much less than a glass, but floating glass should solve that. Will have to be tethered as there is a waterfall.

 

[xts]

It should work. But I would recommend to put the glass partially sunk in your pond, to keep it in the same temperatura as a pond water has and in the same wind conditions.

ADDED>>>
If you have any water/swampy plants (e.g.canes) they may evapourate more water than pond surface. That may be really difficult to include in the analysis.

 

[StringJunky]

Assuming no leaks, a waterfall can be a noticeable contributor to evaporation I've found especially if it's wide enough and direct sunlight hits it. My brother's waterfall was made of 5 paving type slabs arranged in stairstep fashion and had direct sunlight on it.When I turned it off the water level reduced over time much more slowly...it was thoroughly checked for leaks and found to be ok beforehand. You could do two test periods , one with the waterfall on and another with it off and see if there is a significant difference but be mindful of humidity and rainfall variations over the test period.