Ponds in the Greenhouse

[schwing]

I have a small 10'x16' greenhouse attached to the south side of my house. When it heats up, and the fans kick in, all the humidity is sucked out of the greenhouse. I have a cheap misting system installed that kicks on 4 times a day for about 15 minutes each time, but the humidity still isn't where I would like it.

Anyway, I visited a commercial greenhouse and it felt really nice. He had some homemade ponds that went the length underneath his benches. I was thinking that maybe I would install one of the pre-made pond forms in my GH, but was wondering how much humidity it would actually add. The kit I'm looking at is 50 gallons.

Thanks for any comments.
-ken

[BikerDoc5968]

I have an 8 x 15 GH with a treated wood floor over a sand base and 2" of styrafoam insulation. I am constantly watering and misting the plants and floor and, like you, when the exhaust fan comes on the humidity drops through the floor.....so I don't know how well this would work. I'm going to try placing a volume of water in front of a fan so the air movement over the water will cause evaporation....kinda like a "swamp cooler" (I think that is what they are called).

[littlefrog]

Heh... I am guessing you mean me.

I'll tell you how I built my 'ponds', and what I'd do differently when I build them again. They aren't really ponds in the traditional sense, they are really just holding pools for water. Not enough light to grow any plants in them, since they are under the benches. But yes, they do increase humidity quite substantially. Perhaps a bit too much in the winter.

So, 'pond' construction 101. I put down two courses of cinderblock. $0.85 each at home depot (probably more now). I already had a relatively level gravel floor, so I didn't bother to do anything but line them up reasonably straight and stack them neatly. That was about... oh, 15 trips to the home center in my little mini-suv, but I did that for a few weeks on the way home from work so it wasn't out of my way.

The liner is pond liner. Heavy duty stuff I bought on the internet. I can try to find the source, but it is on my other computer. Look around a lot, the prices vary quite substantially for the same product, and shipping distance makes a big difference. I laid the block based on the width of the liner, so I wouldn't have to do much cutting. Only real trick is to keep arranging the liner as you fill the pool with water. I put some flat concrete cap blocks on exposed edges to keep the liner in place, but under most of the bench it is just draped over the edge a bit.

You need to put in some fish. I spent good money on Koi (they were on sale, but still...). Then I killed them. I replaced them with a dozen $0.15 supermarket goldfish. That was a much better investment. They eat mosquito larvae, and you want the fish, trust me.

Now, if I were doing it again... I would dig down about a foot or two if I had the energy. Still two blocks high, just looking for more depth. I had pondered putting in a layer of foam insulation board under the ponds. I even bought it, but didn't do it because I didn't want to lose depth. I really should have, and I will next time. Another thing that would be nice is a aeration system to keep the ponds from getting stagnant. Something I've given consideration to is a simple water fall (or even a sprinkler that drains into a basin) set up to fall from somewhere near the top of the greenhouse. Or several. That would do a better job of trapping some warmth (or some 'coolth', as the climate dictates). Well insulated pools could also be used as active heating sources if you invested in some of the same technology they use for solar hot water heaters... All sorts of possibilities.

[schwing]

Hi Rob! Yup, it's your greenhouse I'm referencing, and thank you for remembering our visit!

Does just having the pools increase the humidity or does there have to move some sort of movement with the water to increase the humidity? I was thinking one of those little pumps that's kind of like a sprayer. Don't know if they are just decoration or if they actually serve a purpose.

I think I would also like to put some fish in there as well, if only for aesthetics. Aren't Koi just big goldfish? Wondering if I just got some small goldfish if that I could call it a Koi Pond once they got to a certain size.

Thanks!
-ken

[littlefrog]

I think koi purists would have trouble with calling goldfish koi, but they sure are cheaper!

I do not have any active system, it is just humidity coming off the ponds by natural evaporation. A little sprinkler or waterfall would add a lot, I bet.

[bonsai1504]

if you get fish you're going to need a filter and a fountain. koi can get really big do i'd go with some shubunkin goldfish

[Bolero]

Hey littlefrog,could you post pictures of the 'ponds'? Or is there a link to them?

That sounds very interesting.

[Gin]

My pond is a half barrel with a pump in it that goes to a shell on a shelf that drops the water back into it . Nothing in the barrel mainly because of spraying off and on and debris from plants . Nothing fancy but does evaporate ,raising the humidity .. Gin

[AHAB]

You may want to rethink the pond idea...

One of our society members has a pond to keep the humidity up... but he is plagued with literally hundreds (he says thousands) of frogs. They are pooping everywhere and causing all kinds of problems. Breaking spikes and such.
You may consider a "dry pond" where you have water fall into a pit filled with rocks. Put a pump at the lowest end and cage it off so you can service it when needed.
You get your humidity rise, pleasing sound and no mosquitoes or frogs...
Just my 2 cents.
AHAB

[Ross]

Traverse City! Well, I have a couple comments. I wouldn't do the pond thingy if it were me. If you are still having a humidity issue, then I would up the misting and try to seal the greenhouse. Problem with the pond idea up this way is freezing or "sucking" the heat during the winter. I haven't seen your setup (that I recall) so I may be way off base, but I like the idea of more misting.