Is anyone using a "Chinese" style greenhouse with a reflecting pond to help with the light level?

Has anyone tried putting a small reflecting pond in front of their "Chinese"style greenhouse to reflect more light in the shoulder seasons? My shoulder seasons tend to be wet and cloudy, so everyone seems to think that only having glazing on the south won't give enough light for the plants, and I'm only aware of 1 greenhouse locally with an insulated north wall, and *all* his grow beds were under the section covered with glazing (long sloped south roof fully glazed).

I'm thinking that if a shallow pond was installed in front of the greenhouse, it would reflect light the way snow does. In the summer, I can let Lemna (duckweed) cover it if there's too much glare, or just let it dry up until I need it again.

While I have not tried a reflecting pond, this idea of using reflected light effectively for improving the light level for photosynthesis is something that I'd like to know more about also. In the thread: Albedo in Permaculture Landscape: Strategic Use of Black & White, I learned from Daniel Ackerman's experience and a link that he provided that different surfaces and colors may offer more growing power. Snow and water have very different reflective properties. If you want to bounce what little light you have off of a nearby surface to provide more sunlight to your plants, white (like snow) would provide more of the spectrum than a pond's reflective surface.  The following link is also helpful
https://climate.ncsu.edu/edu/Albedo
For my mini-grow-house, I am using flat white paint on surrounding surfaces to optimize the light that the plants receive in winter.

Amy Gardener wrote:While I have not tried a reflecting pond, this idea of using reflected light effectively for improving the light level for photosynthesis is something that I'd like to know more about also. In the thread: Albedo in Permaculture Landscape: Strategic Use of Black & White, I learned from Daniel Ackerman's experience and a link that he provided that different surfaces and colors may offer more growing power. Snow and water have very different reflective properties. If you want to bounce what little light you have off of a nearby surface to provide more sunlight to your plants, white (like snow) would provide more of the spectrum than a pond's reflective surface.  The following link is also helpful
https://climate.ncsu.edu/edu/Albedo
For my mini-grow-house, I am using flat white paint on surrounding surfaces to optimize the light that the plants receive in winter.

I don’t know of anyone employing this technique. I installed silver reflectix insulation inside my Chinese greenhouse in the back walls to boost light levels.

I also supplement light levels during our cloudy winters by installing LED grow lights that come on at the end of each day.

Dan Chiras wrote:

I also supplement light levels during our cloudy winters by installing LED grow lights that come on at the end of each day.

I have found in the past that supplemental lights don't seem to do much unless they're quite close to the plants. Then I'm concerned that during the day, the light fixture will actually block  some of the light you want to get to the plants. How do you manage for that?

When I'm starting seedlings, it's usually in small quantities, so I have a fixture in my living room window hooked to a couple of pulleys and the whole family knows they're to "lower the plant lights" when the timer turns them on. I'm not sure how I could manage that for a larger greenhouse and much more 3 dimensional plants than seedlings.

Yes, white to reflect the grow spectrum in the surround might be unusual for greenhouses but studying the albedo effect seems to be a much needed topic for investigation - a community research project directly related to the pond idea??? White paint is a lot less labor intensive and costly than building water features or employing plastics that reflect. A test pond could be a few inches of white rock or sand.
Recently, several other publications have talked about scientists who are attempting to keep climate cool by reflecting sunlight back into the atmosphere. They want to keep the snow and ice from melting. You might enjoy this article on BBC.com https://www.bbc.com/future/article/20200923-could-geoengineering-save-the-arctic-sea-ice
This quote from the article struck me as related to the reflecting pond idea:
"Over the past decade, [engineer Leslie Field] and her team have scattered the [white] silica spheres over several lakes and ponds in Canada and the United States, so far with encouraging results. For instance, in a pond in Minnesota, just a few layers of [white] glass powder [white sand] made young ice 20% more reflective"

Amy Gardener wrote:

White paint is a lot less labor intensive and costly than building water features or employing plastics that reflect. A test pond could be a few inches of white rock or sand.

That's a point. It reminds me of 35 years ago when I bought a house and the builders had left a narrow strip of about 6" between a walk way and the side of the garage on the west side. I figured in the short term, nothing was going to grow there without a lot of help, so I bought decorative white "gravel", dug out the top layer of clay, and put it down. On a sunny afternoon, the glare of those sparkly white stones was down-right painful. When I identified a second area  which needed similar treatment, I used dull river rock and there was no glare issue. (I hadn't even heard the word Permaculture in those days - but as short-term solutions, they worked.)

The plan I'm working on is more a small potting shed/over-wintering shed that if I use some free sliding patio doors on the south wall, could expand my ability to start seeds in the spring. We have a very slow spring, so warm-loving plants need a little help. I would love a full-sized greenhouse, but I know that's not in the cards right now. A friend of Hubby's abandoned an ABS canoe at our place. I figured if I parked it in front of the patio doors, when our sun is at a low angle in the spring and fall, it would help me catch more sun. So no real expense, I can mostly catch rainwater in a barrel for when the drought hits, but is it worth the effort? As Amy points out, a light-coloured path in front of the window might do as much or more. I'll continue to ponder this!