Backyard Aquaponics
A place to discuss aquaponics

Yea, me and my experiments.

So outside I have a couple coolers set up with water and thermometers. One cooler is just sitting there as the control. The other has some black tubing hooked up (taking water from the plug hole near the bottom of the cooler, running out on the driveway in the sun and then back up over the top edge of the cooler.) I managed to get a small amount of siphon going. Really hard to tell but when the sun is shining on the water I can see the slight heat waves in the water flow from the tubing in the shadows through the water.

The water in both coolers started at about the same temperature. I mixed the water between the two as I was filling them. They are close to the same size and I filled them close to the same depth.

When I went out a little bit ago to see how they compared, just by sticking my hands into the coolers, I can say the surface of the water in the one with the thermosiphon is lots warmer.

Both coolers are sitting open in the sun next to each other. The one with the thermosiphon is up on another bin to let gravity help a little getting the cooler water to flow down into the black tube so the warmer water will flow up and back into the cooler.

So why am I tinkering with this idea. Well, my "heater sump" for the indoor breeding system has helped a lot with the temperature for that system but it still isn't quite warm enough for good breeding action. I figured if I could warm the water up more during the day (and shut off the valve to the thermosiphon tube at night) and insulate the sump a little more to hold the warm water temp overnight, then perhaps I can get the water up over 80 day and night and get the breeding going on!!!!!

That is of course if I can find some of that food safe black tubing locally for a good price.

Oh, no extra pumps or electricity required since the tubing will be on the ground below the sump rather than up on the roof for this situation. Hence Thermosiphon.

current temp in control chest 78 F
current temp in thermosiphon chest 84 F

just a couple pics of the set up.

control chest at 80 F
thermosiphon chest 85 F (in the bottom of it)
and 90 F (near the surface of the water)

control 81 F
thermo 90 -95 F

Ok, Dappled shade starting to shade the coolers but the black pipe still running out in the sun. The pipe is only like 40 feet long by the way.
Ambient air temp in the shade right now just under 92 F
temp in control at 81 F
in thermo 93-95F Actually the very thin layer on the surface must be much hotter than that since I had a slight ouch reaction as I put my hand into the water to grab the thermometer this time.

Well, I think I've found some pipe I could pick up for the project on the heater sump
http://www.lowes.com/lowes/lkn?action=productDetail&productId=24166-000000150-24166&lpage=none

My main reasons that I hadn't continued the research into my solar heater ideas was that I didn't trust the black irrigation tubing I have (since it said not for potable water) for heavy use with hot system water.

Now that I've found black pipe that is rated for potable water, at a reasonable price, and should be able to stand at least some sun and hot water, I'll try it.

92.3 F in the shade
control at 82 F
Thermo at 95-100 F

I think I'll need to keep a close eye on this set up if I hook it to the aquarium sump. I don't want to cook my fish, just get them hot and bothered.

Ok, got back home, the stuff is now in the shade.
The air temp is 91 F
control 84 F
Thermo 101 F

Definitely useful.

You do great things Lynx

Have you thought to possibly have a heat exchanger on the fish tank side rather than having it hooked directly up to the thermosiphon?

Perhaps use your esky (cooler) as you have it, but hook the fish tank up to a coil placed in the esky and pump the fishtank water through that. This should give a bit smoother temperature change and possibly reduce the chance of mishaps with the water - those thermosiphon tubes are a bit exposed... You could then use not so safe (cheaper?) tubes for the actual thermosiphon.

It would be safer to use a separate tank and exchanger for heating. Definitely long term. Right now I'm trying to get a quick fix on heating something without adding extra pumps, or containers into a small system.

For now I'll do this quick and dirty method. (if something happens to the pipe and the sump drain, I'll only be out the one small pump. The system is CHIFT PIST so no worries about draining the fish tank water. Actually the system could probably use a bit of a water change anyway.) I picked up some 3/4" black drinking water safe tubing today so hopefully I can tinker a bit more and report on the results tomorrow.

If this works well, I'll be looking into the active solar heating for the big system for winter using the freezer as the storage tank and hooking up some sort of heat exchanger loop to run through it. That one will need to be active with a pump since the best space for winter solar heating is going to be the roof.

Nice experiment TCL
91F in the shade? sheesh we`re not even making 70F in the sun

If black correx is food safe (made of PP i think) its almost a ready made solar panel...barring the manifolds and probably cheaper than pipe.

I don't know what correx is. I got 100 feet of 3/4" tubing and the fittings I need for under $25. Will see if I can get my aquarium system to between 84 F and 86 F tomorrow.
See the trouble with the aquarium system is that it is indoors and we usually don't keep the house that warm.

I've found that the heater sump (the blue barrel outside the window in the sun) has been able to bring the water temp up to 80 F in the aquarium on hot days like today. Problem is the temp drops back down overnight. I'm thinking that if I insulate the barrel some and control the thermosiphon with a valve (will have to do this manually for now) to stop it getting much over 86 F, then we might be in business for breeding.

One step at a time anyway. See how well I do at getting the thermo siphon to work on the barrel sump with the larger tubuing running around in the front yard rather than on the driveway.

i guess it may be called Coroplast over the pond.
http://coroplast.cat-x.net/CategoryListView.aspx?id=1
Its a polyprop fluted board a bit like twinwall polycarbonate glazing but lighter and cheaper 5 sheets = £15.