I did a search first for threads on greenhouse glazing materials and UV filtering, but most were older threads and none specifically dealt with what type, brand, rating, etc., of material would be preferable for a greenhouse. Now that I've got my electric panel upgraded and have a generator back-up installed, the next step is a small starter greenhouse - likely a kit like RION in a 8 x 24 size. How do you determine if the glazing material is acceptable or not? No one wants to use something that will screen out too much beneficial light for the corals. I remember that there are ratings for plexi, but how bout greenhouse mfrs? Any leads are appreciated. Hope to move out of the basement next spring - the inventory has out-grown the space!!!