karenrei, I don't have a hoophouse, each wall and the roof are totally seperate segments as to R value, covering etc. stressbaby nailed it on the head on this thread http://forums2.gardenweb.com/forums/load/strucs/msg0909104730738.html and I am surprised that thread did not get more input. Identify areas where improvement can be made and fix them. Then look at the whole structure again and work out where the "new hole" is. On the thread about the polystyrene sheets, http://forums2.gardenweb.com/forums/load/strucs/msg081128491250.html I tried to point out that adding an R3 insulation to one wall was great, bumping it up to R6 may be a waste of money because there may be another place you could put some R3. Yes, In retrospect my south roof (and sorry to use trade names but people can look it up and understand it better) should have been Tufflite IV outer, pool cover and then Tufflite infrared on the inside. A nice sandwich and cheaper and easier to install then polycarbonate triple wall. Yes I know polycarbonate triple wall will last longer but, it is also very expensive. I had a standard double poly inflated south roof so I gained some insulation advantage but all of that insulation was lost by a breach of the outer layer. (see my rant on this thread) http://forums2.gardenweb.com/forums/load/strucs/msg0409365924489.html OK, so I know I am going to lose light on the south roof because of this sandwich but I am going to get a boost in insulation, and because of the bubble wrap sandwich I am also going to get some protection from damage. The sections would be 2ft by 8ft and if I had a breach of the outer skin then my south roof loses 1/12 of its R value not 100%. Next, as in reducing light transmission, as you say most of the light in spring is through the south wall, so a reduction in light transmission in early spring of say 15% from the south roof is still a loss but a small loss as not much of the total is coming in that way. ""any areas that don't get much sunlight being as heavily insulated as you can with opaque (preferably reflective, in my opinion) insulation."" North wall is solid and painted white inside (reflective). Half the north roof is solid. Changes to my configuration next spring? 1, Shade cloth hung vertically inside about a foot from the south side to reduce the tendency of young plants to grow towards the south side but as the shade cloth is on the inside it will block light to the plants but still contribute to raising the air temperature in the greenhouse. 2, Wait until the corn and bean crop is harvested and there is snow on the ground and then set fire to my old barn to the south where the shingles that hit my greenhouse in high winds come from. (insurance company please note, that was a light hearted attempt at humour.) Umm... on second thoughts, I will insure my greenhouse! :)

We do plan to spend more time in the greenhouse. Only trouble now is that by the time we get home from work, it's dark out :( As far as costs it's easy to see our heating costs are drastically down, but not easy to calculate exactly how much. The GH shares a propane source with our garage & studio which we are heating about the same as last year. Just a rough estimate but we have two 100-gallon tanks that cost about $500 to fill. By this time last year they had been filled once and were about 50% full. As of Sunday, both tanks are 60% full and have not been filled yet this heating season. I don;t know this years propane rates but I'm hearing they are pretty close to last year. I'd say that's a significan savings. Keep in mind we did see an increase in our electric bill by about $20 per month for late Oct & Nov when we were only heating the GH with electric. Even so I'd say the savings in just a few weeks in propane have already paid for the solar pool cover. As an added bonus, we're seeing much more reliable GH temps so we can start to us ethe GH more. In fact we're planning to start some salad greens from seed this weekend. Our tomatoes are starting to fade and our cukes are fading also. Any other suggestions for winter vegetables? We don;t plan to add supplemental light so I know we;re limited by that but I'm betting there are crops that will grow even now.

Our pool will be done **hopefully** within the next two weeks here in NY. Hoping the weather warms up so we will be able to actually use it. It has been a cool spring for sure. cncguy - not to hijack, but have your pavers been installed yet? Any pictures to share?

We must turn our pool off for a 7 day vacation in July (PA). Would it be better to leave the solar cover on or keep it off? We have a fiberglass pool and I was planning to put extra chlorine and algaecide in it and hope for the best. We normally never have any issues and always have sparkling clear water. Is there anything else I should do to prepare for 7 days without the pump running? I know we should leave the filter on it's regular cycle but this time we cannot. Thanks in advance for any help!