Bellaroo, I have a pond in my greenhouse and I have been using the water to water my plants and intend to continue with using the pond water. If you have fish in your pond it makes for healthy plants as they are getting fertilizer too. Using the pond water will allow me to continually perform 30% weekly water changes to keep my fish healthy. I was not going to respond to all the additional posts as this is a rather old post. However, I have noticed a few things with my pond and thought they may be useful for anyone just beginning the planning stages for a greenhouse and perhaps an indoor pond. 1. I had only 15 to 30% humidity in my greenhouse prior to adding the water in my pond. Please note where I live. It is very dry here and we very seldom have much humdity. It has increased my humidity to a very high rate 60's and 70% humidity sometimes even higher requiring me to turn on my exhaust fans. 2. If you have a wooden structure (as I do) think twice about a pond OR make sure you are using a very good primer and outdoor high gloss paint. I am flabbergasted at the amount of moisture that just drips off the polycarbonate panels I've framed into the ceiling, not to mention the moisture which drips from the walls. 3. I had initially thought the water in my gh would heat up drastically from the sun during the day and produce an abundance of heat during the evening. Not so, perhaps it's the depth of water I have. My pond is 4' deep to house my Koi for the winter months. The water has never really heated up and I can't see an enormous amount of heat that the pond is giving off into my greenhouse. 4. I tried building my pond so that I would not waste a lot of space in my gh. I built it so that if I run out of room I could build a table or plant shelves over the top of my pond allowing me to use all the space I'm using in other parts of my gh except the floor directly under the table/plant racks over my pond. Just a little food for thought when considering a pond in your greenhouse. Honestly, I love mine and hope to keep it. However, if it causes damage to my structure, I will fill it in, or just not fill it with water for one year to see if that makes a difference. Happy Greenhousing Everyone! ~Tj~

I'd like to ask more about your greenhouse and hope the move went well. It is the same model I am thinking about to add to a covered porch. I will enclose the sides of the existing porch, then add this attached greenhouse out to the south. There will be some work space under the old porch roof, with a door coming from the house. There is also a picture window looking into it that happens to be from my bedroom. It will be easy to allow for heat exchange between the house at times with the door and window. I've thought about this for some time but haven't gotten around to doing it. Would appreciate any input about the situation and also opinion on the Sunglo or other attached models. Would really like to see a picture of your greenhouse if possible.

I laid a used common brick floor on a concrete footing but only brough in a single water line and the drain line through the concrete. The drain (obviously) has to be embedded in the ocncrete but not the other services. I used 3" drain pipe (rather than small, more common 1 1/2" so that I could more easily flush out debris...I stepped it down to the small size for the small sink in the corner. For your size gh I'd do what I did for electrical (or phone or whatever), use good quality liquid-tight conduit and run the electircal outside and into the gh where you really need it. Easier to change the conduit locations that way than buried in the floor.

boxcar, The foam is waterproof, so if you lay it under crushed stone with no place to drain; it won't. However, if you have the patience to fiddle with the crushed stone, grading and packing it firmly to the center or one end and can dig out a drywell, you could lay the foam over it, leaving the top of the drywell open from the foam, then more stone on top, and the water would drain to the drywell. But it would result in a much nicer and easier to keep clean floor, not to mention tracking the stuff, to just overlay the foam with concrete patio blocks or bricks. As long as the crushed stone is well and truly packed, the foam really will support the bricks or blocks, that will lay easily and could be butted tightly to avoid the need to fill between them. You could even broom mortar into any cracks, wet it and when it dried, would have a really solid floor. BTW, just in case you aren't familiar with drywells- They are just holes dug down to below frost line, lined in the old days with mortared brick or stones and now, plastic liners that can be bought for the purpose. Or, you can use a length of fairly wide plastic culvert pipe. You could also use the same heavy plastic channel drain as I did, except that instead of the section with the drain drop leading to a sump pit, it would go directly into a drywell. There are a number of options, but for any drywell, always- the deeper the better, then fill it with large stones to the top of the liner and either set a made for the purpose cap or channel drain drop section over it, or top it off with with 1/2 inch hardward cloth and lay a piece of window screening over that, to prevent anything other than water from seeping into it. I drain my GH with a channel drain that connects to a sump pit, fitted with a sump pump, that empties the pit to a 150 ft. long line, but I fitted out my GH out to serve as a tropical fish hatchery, so often need to dump hundreds of gallons of water at a time, and have a large utility sink out there too, with H & C water, so it's a different GH use and set-up than most. I also laid OSB over the foam, then topped that with 3/4 inch concrete board, but that was because I wanted a glazed quarry tile floor and it requires far more elaborate under pinnings than do patio blocks or bricks. The tile also lines the kneewall, but there too, my needs were different. All you really need for a GH in which you only grow plants, is a means to drain off excess water from the plants and avoid too much dampness that might cause fungus on them as well as the interior walls of the GH, although the ability to hose down a concrete block or brick floor with cold water is a nice extra, for keeping the GH clean and help cool it on hot days. It really all depends on HOW you want to use your GH, and WHEN in relation to your climate, and how much time, effort and money you are willing/able to spend to fit it out for your own maximum use and enjoyment. After all, a garden GH is really only for pleasure, because unless you are feeding an army of kids, for what it costs to build and maintain one, it's cheaper to shop for veggies at Whole Foods and buy started plants at any nursery. So by all means, put a lot of thought and effort into your foundation and if, after you have the GH you need to back off on the fittings until your wallet recoups; do so and in the end, you will have what you really want. We spent an entire season preparing the foundation for my GH and by the time we actually got to erecting it, all we had time for before winter set in was to install the heater, but as anxious as I was to use it, patience paid off. (Of course, we are also a pair of arthritic old poops, so everything takes us longer now.)