farminggreen: Presuming your use of the term "aquaculture" means growing fish for the table, unless you live in an area that never drops below freezing, I would have grave reservations about using aquarium heaters to raise water temps high enough to radiate sufficient heat to serve as space heaters, without heating the water to a degree that would kill the fish. Also, aquarium heaters are not really made to raise water temps much over 10 - 12 degrees above ambient air and why every Discus breeder I know has to use multiple heaters in their larger tanks, or risk having their 90 deg. loving fish keel over in winter, even with room temps in the 70s. I suppose it could be done, but you could end up spending far more on the heaters and electricity to run them than if you simply installed a space heater in your GH. So it's really a case of your expected air temps and the volume of warm but not hot enough to kill the fish water necessary to radiate enough heat to warm your GH. However, also keep in mind that regardless if baseboard, old fashoned cast iron stand ups, or underfloor- radiant heat circulates hot water or oil in a closed system. Fish need as much open surface as possible, which also accelerates both evaporation and heat loss. The cooler the ambient air in relation to the tank, the faster it will evaporate and require topping off, and the more wattage to maintain the optimum temp. for the health of the fish.

Model 69893 is the newer version of the Harbor Freight 10x12 kit. Model 93358 is the older version of the Harbor Freight 10x12 kit (I have this one.) There have been some small changes to some of the parts (doors, floor plates, ceiling plates) and the shape of some of the back panels have changed. I'm not really sure what spurred these changes, and I honestly don't know why one would be any better than the other. That said, I guess I'd probably choose the newer model, only because it seems logical that HF might discontinue replacement parts for the older kit, before they discontinue parts for the newer version. The manuals are a bit different for the two versions. If you get your kit and some of the parts don't seem to match what's shown in the manual, you can download the correct one from the HF website. (I've had a few emails from folks with confusion resulting from having the wrong manual.)

Randy, although you don't have to prune HF Young, you may find in your hotter zone that it will get severely browned out in the middle of the summer regardless of how much water you give it. If this happens, then you can cut it back by at least half, keep it watered and fertilized and you will more than likely get a totally new flush of blooms late in the summer. Last year, with the drought in the southeast, most of my type II clematis, which the President falls into, were severely browned out by the end of the summer. In January, when I prune my clematis, I treated all of my type IIs as IIIs and cut them back almost to the ground. They all came back up and bloomed just wonderfully for me this spring. Clematis don't read books and often do things that defy the rules about pruning that are written about them. Use your common sense and learn to experiment with your clematis and you might be surprised to find how many times you can get your type II clematis to rebloom. I know that Jeanne who lives in Texas and does this can support this idea!

Hello azee_2009, OK I originally thought it was going to be a rooftop greenhouse, but after rereading your second post I wasn't sure anymore. As far as the construction I used to build mine, it could be applied to a rooftop situation. By just building a sturdy base for the electrical conduit posts/poles. Similar to the baseboards I made for mine. The weight of it will keep it in place. The poles for my greenhouse only go down in the ground about 8-10 inches, and there is no cement holding them down (just the weight of the greenhouse structure itself). I just posted the link/information to give you some ideas. That greenhouse looks much nicer than the one I built. Although much more expensive too. Not including the subterranean system, and the hydro systems inside, I built my whole 10 by 20 foot greenhouse for about $800. Ya, heat will be challenging. Our outside temp today was about 92 degrees, but the temp inside the greenhouse was 108 degrees. When the temps here reach the 120 mark, greenhouse temps would likely be around 140-150 if I didn't have a multi tiered cooling plan. Cross ventilation is great in some circumstances, but it wont help much at all to blow 120 degree air on your plants when it gets hot. Given the best circumstances, swamp coolers may bring the temps down about 20 degrees. But if humidity isn't carefully controlled, they may only provide a difference of between 5 and 10 degrees at most of cooling effect by themselves. Just to clarify, when I mention high humidity, I mean in the greenhouse. That will depend a lot on temperature inside the greenhouse, water vapor given off from the hydroponic systems inside. Not to mention the biggest factor, how many plants your growing, and how big they are. Plants breath out water vapor (called transpiration). The water vapor (relative humidity) in the greenhouse will get higher and higher unless it's ventilated. But ventilating a cooler greenhouse with the (hot) dry outside air will only heat up the inside of your greenhouse. I have searched the web a lot & every where i have read that Double Poly Sheet that makes air pockets between them retain heat within the greenhouse & reduce heating costs about 50% compared to single poly coverings. So how would i be able to use it. As i have to fight against high temperatures. The air pocket in-bitween the two layers of poly is an insulation pocket. Air pockets are the best insulation there is. Insulation will protect against heat just as easy as it does against cold. If your greenhouse is cooler than it is outside, the insulation (air pocket) will help keep your expensive cool air inside the greenhouse stay cooler longer. If you have no way to cool the inside of the greenhouse, then it wont help much. The air pocket is just insulation, not a cooling or heating layer. It just helps block the heat transfer from one side to the other. Blocks heat from getting out during winter, and blocks against heat from getting in during summer. The 4-5 inch's between both layers you describe should be plenty. Typically it's only about one inch between layers. Though I would expect that you will still get much better results with a air blower between the two layers. The reason is if you blew the cooler air in between the layers, it won't give the air pocket a chance to heat up. Thus keep the heat transfer between the inside, and outside layers to a minimum. I want to know the link & name of software you are using to create 3D images. I want to download it to make someone understand what i mean. I use a free program called Google SketchUp. They have a pro version you can pay for, but I've always used the free version, and like it very much. I save all my drawings into a folder so I can expand on them later without starting over. Before you post your drawings, you'll need to remember to export and save it as a 2D image. Otherwise it wont be in jpg. format, and people that don't have Google Sketchup wont be able to view it. Before I built my greenhouse, I did a lot research online to figure out what would work the best for me, as well as my budget. Here are a bunch of the links I have got bookmarked from those searches. I know it's a lot to read over, and it's been a long time sense I looked through it myself. But a lot of it is in lists of topics. I just read through what was of interest to me. Arched Greenhouse PRESENTATIONS REFERENCE SOURCES Horticultural Engineering Greenhouse Energy Cost Reduction Strategies POLYTHENE GREENHOUSE FILM FACTS Chapter 11- Greenhouse Site Selection Chapter 12- Greenhouse Structures Chapter 13- Greenhouse Control Systems Chapter 14- Greenhouse Energy & Resource Alternatives "Greening" the Greenhouse Greenhouse Glazing Greenhouse Energy Conservation Strategies Greenhouse Energy Conservation Strategies: Temperature and Scheduling Managing Greenhouse Temperature