You can get different "additives" or treatments to poly that help in the GH. One is an anticondensate treatment that you mention above. Another potentially important one is UV treatment, which may extend the life of your film. Another feature of some films is IR treatment. Solar radiation exists as UV, PAR (the plants use this) and LIR. The heat that builds up in the GH during the day is re-emitted at night, but only as LIR. Regular poly is relatively transparent to LIR, so you lose heat more quickly at night. IR films are relatively opaque to LIR and so they will hold the heat better at night. Glass and PC are opaque to LIR, BTW.

We used to refer to that as overwintering film and replace the transparent film on our perennial house to this to help the plants maintain dormancy. Overwintering film is not meant to last for years as regular g'house poly.

I have had a solar water storage greenhouse for over 6 years now! I have a A frame type made with 2 by 4's and double 4 & 6 mill plastic ! Its about 8 by 20 and has about 400 gallons of water storage.I keep some cold hardy plants like lettuce all winter and maintain a temp about 28 at the lowest. I plan on starting seeds by the end of Jan and have what I think is a great idea for keeping a heat chamber inside my greenhouse. I am using a 5 foot bought greenhouse with shelves that will be set up inside the main greenhouse. Inside this small greenhouse I will have a 30 gallon aquarium with a aquarium heater that heats the water to above 60 all the time. The heater is only 50 watts and will not cost much. I think the advantage is moisture and heat for a very cheap price. Aquarium heaters are very cheap less than 420 and are very accurate. What do you think?

I do not think anything can glue polycarbonate. I've tried many glues that claim they work. None I've tried do. Possibly, with woven materials, an engineer could come up with a product that could hold two components together. I have not found any Chemists that can in six years of looking.