Fiberglass transmit enough light in g-house?

Does the milky-white corrugated fiberglass transmit enough light for plants to actively grow? I'm talking about the stuff that's on the roof of my greenhouse in the pic below (hope you can see it). Also, I'm talking about active growing in a heated house, not just overwintering plants. I always thought that stuff transmitted plenty of light for plants to grow, but today while calling around for prices, one person told me it wasn't enough, I'd need polycarbonate (that clear as glass stuff). Is this true? I don't think this person was a very reliable source, but you never know. Besides the two above, what about that frosted-looking corrugated stuff, looks like a frosted shower door and half the price of the clear polycarb ~ enough light for growing? Anybody know the % of light transmission for any of the above?

I use fiberglass on the roof of my greenhouse and find it works just fine. Plants don't stretch. Will admit that I did put two small clean windows in the roof too. I checked when at our local greenhouse and they are using the milky white glass too. There is a small picture of my greenhouse in the thread "No Brugs Growing Here....." I think it is the same stuff you are using.

Do you start seeds in there with good results, Brugie? I'm concerned with that as well as I want to grow tomato and pepper transplants, lots of them, for sale.

Wingnut,

I start everything in my greenhouse. Vegie and flower seeds, cuttings, etc. I have never had anything get leggy and have had tomatoes and peppers get large, but they stay strong. Good luck with your spring plants. I think you will be fine. If it doesn't work for you, you could just replace a couple of panels to let more rays in. I find that with tomatoes, holding back on the water almost to the wilt stage makes for stronger trunks. I've picked up some helpful hints over the years from some good friends who have 13 greenhouses and obviously are retailers.

Brugie, that's exactly how we control teh height on our tomatoes in the green house. I learned it from Van Wingerdens in NC. They have 13 acres in one range.

Well, isn't THAT handy?! Thanks, y'all! Cala, do you have fiberglass on any of your houses? What's on the rest of them? How's the light transmission?

Brugie, found your picture (pretty scene!) and it does look like it's the same stuff I'm using ~ regular old corrugated fiberglass sheeting.

Kenny got more lumber today, so we'll be re-doing the front wall, closing up more glaring holes, getting ready for the addition. We're waiting on a friend's tractor (ours is in the shop) to level the ground. Hopefully we'll be ready for glazing late next week.

Wow! If the milky-white corrugated fiberglass allow enough light for Brugs, double canal polyethylene windows may do the same. I gave this serious thoughts the entire January. I want to use it for the new greenhouse I have spoken of, but was not very shure that it would emit enough light for growing Brugs with flowers and onset of fruits. Now I think that I will give it a fair try. Polyethylene windows are more exspensive than glass, but much more inexspensive to heat up during winter ... besides, the poly`s can be bought in 1 x 1 sq-m and easier to build with.