Just started a deep-water model here in Phoenix area. I was told by the hydroponics experts here that I could not do it because the water would be too warm. (Outdoors temps in summer here can hit 120 degrees - pool water gets in the 90's)

So the challenge here would be cooling the water and shading the plants. (I use shading material overhead like they use at the nursery.)

I'll post pictures soon, but I used a 40-gallon reservoir I had handy, 10-ft long thin-wall PVC with holes for 3" pots, a pond pump and aquarium air pump/stones.

For cooling - I diverted the pond pump to a 1/2 inch tube with 20 mister heads INSIDE a 10-foot thin-wall PVC. One end is open, tho other end has an in-line fan. Air is drawn through the full length of the pipe, cooling the air and cooling the water by evaporation. The cooling pipe is tilted slightly so the cool water from the mister heads flows downhill to a drain which feeds the planter PVC. I keep a slow cool river moving through the plant roots with air bubblers spaced inside.

Yes, I lose a couple gallons per day to evap - but with a 40 gal reservoir I keep all my levels pretty even by topping it off each morning when I go out to check on the garden.

The cooling system is basically a mister system where I'm capturing the cooled water and wasting the cool air. I plan to cover the 10-ft cooling tube with black plastic and turn off the fan to heat the water with solar in the winter. (We have 30 degree nights occasionally)

I'll post pics soon (I just signed up here a few minutes ago and I was not prepared to post pics today.)

Short answer - "Yes, you can do outdoor hydroponics in the heat of Phoenix if you can cool the water a bit" :)

Doug

I understand that aquaponics requires micro-organisms, bacteria and acids to break down the organic material, in order for the plants to be able to absorb the raw nutrients from it. So I don't know what effect warm water has on those particular micro-organisms, bacteria and acids, but I do know that Tilapia is a warm water species of fish, and thrives in warm water. So if water temp is an issue, growing Tilapia could be an answer. They don't do well in cool water (below 60 ðF), but it's a lot easier to heat the water in winter, than cool it in summer.

I personally would consider a recirculating geothermal system to cool the water during summer (even warm it during winter). Easy enough to build, and the only electricity it needs is a water pump. It would just need a good filter (like pond pumps) to keep the pump from clogging (from the organic material), unless it was a closed loop system (but a closed loop system would probably less efficient).

@homehydro:

I considered burying the reservoir ("geothermal") to maintain the temperature of the water... but the reason that homes in metro Phoenix rarely have basements is that it takes dynamite to dig around here... we have this delightful element in our soil called "caliche" which is harder than concrete. I've destroyed industrial post-hole diggers just trying to sink fence posts, so I did not want to dig any more than I have to...

Hmmm - I don't know how to insert pics here yet, but you can copy this link to your browser or click on the URL below.

http://sw-air.com/ArizonaModel.jpg

I built this diagram to explain how I inserted an evaporator cooling tube in between the reservoir and the planter. Missing from the diagram is the air bubblers in the planter, the purpose of this drawing was to explain the water flow and cooling method.

Actual pictures of the finished product to follow. :)

(The model works, my outdoor desert hydro garden is doing wonderfully!)

Doug

Here is a link that might be useful:

Figured out how to add pic... See post above for details. Click on pic to see larger version. :)

It seems strange that the original post here is dated Feb.28, 09 and the 1st follow-up is Aug.4, 10. I suppose onap1 is no longer with us. Oh well, stranger things have happened And this is a good read. Welcome to the forum Doug. America's largest hydroponic greenhouse - Eurofresh Farms is located in Wilcox AZ. If I were in AZ. I would definitely try to hook up with a tour. I heard a story a while back that the science of aquaponics was pioneered in a couple of 55 Gal. drums behind an outbuilding on a college campus in the Caribbean, (maybe U.S. Virgin Isles?) using Tilapia back in the 50's or 60's. If this is true, Aquaponics in AZ. Should be Quite feasible as U.S.V.I. is in a more equatorial location. Oh, excellent job on the graphics. Good Luck.
Ken

deserthydro
I to in live AZ, so I understand how hard the ground is. It's actually more than 50% rock from my experience. I dug a hole for a 32 gallon trash can I use as a reservoir, took me 4 days to dig (and I filled it with water every night). I didn't get down quite as far as I wanted to because I ran into a rock I couldn't get out. I got it 30 inches deep (though I wanted 36). Even so it still works well, as long as the above ground parts where water flows are insulated. I don't know what size setup you were considering, but I was thinking of renting a backhoe to do the digging. I believe I have herd they can be rented for about $60 an hour. At least that's what I remember the guys building our retaining wall a couple of years ago said it cost.

Also I was thinking of digging a trench and laying a row (or more) of tubing in coils in it. Using long trenches you wouldn't need to go real deep, 3 feet should do. The tubing runs about $39.95 for 700 feet at the Lowe's (If I remember correctly). Then recirculation/pumping the water through the coils. Also if your reservoir is above ground, you can pack dirt around the sides of it, that will give some geothermal effects.

Thanks for the picture, what program did you use to draw it? I use "Google sketchup" myself. That's pretty much how I imagined it. I Plan to do some testing using that idea. Have you done any testing on how well it actually works, like before and after temps? Size of system compared to temp drop? Maximum temp drop (compared to ambient air temp)? Getting even more technical, any testing on temp with different water droplet sizes? Sorry for all the questions, living in such a hot climate, I'm always looking for energy efficient ways to cool my nutrient solutions.

P.S. Unfortunately Wilcox is about a 6 hour drive from where I am and I just don't get out that way much. But ya, it would be nice to take a tour (we actually eat their tomato's).

deserthydro
I just noticed your website "sw-air" (I assume it's your website) is not coming up right in Firefox (the browser I use), and the text seems a bit off also. The copyright date at the bottom says 2004, but that could be how long the company has been in existence and not the website. I used to have a link that tested a website in many browsers as well as versions of them, and even with different screen sizes until my computer crashed. So I lost the bookmark. Anyway I just thought I would let you know in case you were not aware of it.

HomeHydro:
Thanks for the feedback on the website, it has not been updated in years... long story.

I like the idea of burying tubing or pipe, it could extend or stabilize growing seasons in multiple climates, not just the desert.

As near as I can measure, I drop the air temp about 20 - 25 degrees with the cooling tube (I'm being conservative here), and the water temp hovers around 76 when my pool water is in the 90's. Since the water reservoir is in the shade under a tree, and 40 gallons deep, it stays pretty stable. One thing I did not mention was that the cooling tube produces more water than the planter can handle, so a cool water overflow pipe returns the unused water to the reservoir. (That is not shown in the drawing, but where the "exhaust fan" part is shown there is an overflow tube 6 inches above the spot where "gravity flow" starts.) This cycle has brought the water temp down remarkably. (Yay, it worked!)

The picture was quickly hand-drawn in Photoshop to explain the project to a coworker.

I live in Gilbert. If you're reasonably near we should get together for lunch or a beer. Maybe we can make the effort to journey to Wilcox one fine Saturday...

Here is the current project, five weeks old. I ended up putting a shade canopy across the top, and building a simple but strong frame of schedule 40 PVC so I could hang my bug traps (the suspended yellow squares) and put strings up instead of stakes. (Strings are more visible in the 2nd pic.)

This entire project was designed to be cheap, cheap, cheap. Seven dollars for the planter tube, same for the cooling tube, 30 dollars in plastic tubing, an old Rubbermaid pickup truck toolbox for the reservoir, 50 for the pond pump, and 50 for the silent fan that powers the cooling tube.

In the first pic you can see the cooling tube a couple feet above and the behind the planter tube, and the reservoir is behind the bench. (Had to make it look pretty too or the wife would have never stood for it...)

Second pic - Several types of pepper plants, I'm growing Jalapeno, Habenero, Cayenne, Anaheim - only 5 week old, doing very well. Note the strings I use as stakes, they work real well in the desert wind.
Cheers everyone!

deserthydro
Thanks for the reply and pictures. Sounds like it works well, trying it myself is definitely at the top of my to do list. I was trying to figure out why it works, and I think it cools by evaporation. I have read (briefly, and forget where) that they have been using clay pots to cool drinking water in some regions of the world. From what I remember as the water soaks through the clay pots then evaporates on the outside of the pots. The evaporation action sucks/takes the heat with it as it evaporates, leaving the water that's left inside the clay pots cooler.

And if I remember correctly they have even refined it to be so efficient that they can make ice with that technology. Although I cant remember what it's called exactly. I was going to look into it but didn't really want to deal with a lot of clay pots, so just never did.

P.S. I would love to get together and talk hydro with a fellow hydro gardener. Although I'm in Lake Havasu and don't know when I will be able to get down that way. I cant afford the gas money at this point. I have some advertising lined up that should get me some carpet cleaning jobs, but it wont come out until October.

You can send me an e-mail at/to
rocketman1022000@yahoo.com

It's my junk email that I rarely ever even check anymore. But I will delete all the spam from it right now. Just put deserthydro in the subject line so I will know witch one is from you. Then I will send you my real email address that I check every day.

I was going to ask this latter but I just reread your post and had another question. The question that I have because I reread the post is I believe you said that the fan cost $50. Is there some reason the fan was so expensive, I can get a 24 inch fan for $20. Is it a special rust proof fan because of humidity? The other question, are the misters inside the tube or go through the outside. If they go through the outside are they easily replaced if/when they clog? I can think of a few ways to design them but I was wondering what you decided on.

HomeHydro:

The fan costs 50 bucks because it's an in-line vent fan. Since I'm drawing air through a tube, I needed a tube-style fan. I could have used many different types - but this one is silent and required minimum modifications to suit this purpose. Pictures with explanations below:

Thanks deserthydro for the great pictures and explanations. It really looks nice also. I like how you have the misters inserted, that makes maintenance easy. We have both Home Depot, and Lowes here in town. I'll look for those misters, and probably do some testing with as many as I can find. I'm also thinking of using the misters used for cooling patios. They give a fine mist, but as you mentioned they do need a high pressure pump to work properly. I'm also thinking that they will clog much easier. But for now I need to start inexpensively, then hopfully work my way up from there.

P.S. I have had an idea for a while to use a small 1500 psi pressure washer, and pressure regulator to step down and controle pressure to the system for an aeroponic system. The electric pressure washer (with submersible intake was $99, and the regulator was about $80 (I was told). But I have never tried it.

Great discussion so far. I was wondering what types of plants you were growing in your system. What limitations are you seeing from growing in a desert climate. Thanks!

I just started a tread asking help from people in phx area, but I also found this tread. I am a newbie to pond/aquaponics. I have started a large design to put a new set up in my backyard. I was hoping to get some help from local people to review my design and give me some encouragement. thanks. ArrowheadEstate@gmail.com

I just stumbled acrossed this discussion and as a newbie was thrilled. Imagine my disappointment when the topic just died out. Did this topic change areas?

Agreed, just getting interested, live in PHX area and would like to hear from anyone having success. Looking at building a patio sized rig.

Can we get an update on your system, deserthydro? Looks great. Would you still recommend it? Are you having success?

Also joining this thread a bit late, but I noticed that Gardenweb has a hydroponics forum but not an aquaponics forum. Anyways, I'm wanting to learn as much as possible as well, and in my searches, I discovered this forum specifically for aquaponics in Arizona; http://community.theaquaponicsource.com/group/arizona-aquaponics. I have already joined and have also found some good information especially concerning the summer heat in the Phoenix area. Hope this helps.

Building my greenhouse using aquaponics design base. Is the water being warmer a big deal with tilapia?

Anyone still doing this?