Backyard Aquaponics
A place to discuss aquaponics

Howdy Bill
The oscars are about $8.00. I dont remember the price of pacu, but At our walmart gourami are $2.50. The kissing pink ones and some of the others get large but not as large as pacu. Also reportedly the pacu wont breed but the gourami will. I just need time and energy to heat the water for them.
Try naming them yourself....fishfry, fish'n'chips, poached, dinner, beer-bater, shake'n'bake. The kids will get the idea and join in the fun.

any updates on the array rupe?

I am wondering, is copper piping bad in a aquaponics setup? I have a copper tube solar collector on my system.

Yes...there's been much debate throughout time and the forum on the subject...

But unequivocally... IMO.... and research... yes....

The effect of acidic AP water only exacerbates the ionisation of copper.... and you need to remember that your AP system is a "closed loop"....

I unplugged my heater today and I am going to make a heat exchanger for it to keep it separate from the FT. Glad I caught this thread before I had any problems. Thanks

Yeah, chuck copper into the search engine - and watch the sparks fly.

I just found this thread as I've been wondering if I can keep water warm enough for tilapia through the winter (mild winters, but regularly dips down below freezing at night here). My system is still imaginary, but I think I'll be putting in a little test system soon.

I did some searching on building some sort of solar collector myself, and found this design that uses pex instead of copper. It's set up as a drainback system, so when the pump isn't on, the water drains out for freeze protection, but also will prevent the thermosyphon problem of overheating fish when pump is off.

http://www.builditsolar.com/Experimenta ... uction.htm

HI Rupe +1 I just finished reading this thread. Early on I was getting ready to fire off a comment about the PVC pipes. I see you already noticed the problem with the heat. Doesn't take much does it to bend the stuff.

The first thing I noticed was that you did not have both ends in the water. They both need to be in the water to maintain the loop liquid full. Getting the loop full in the first place can be difficult if the flow rate is too slow and then you have a tendency to drain out the outlet side.

The second thing is that the sun will heat the metal hot enough to melt your PVC which you already know now. I suspect that you will have to use a Stainless Steel Tubing for the piping. A grade higher than 304 because of the tendency of Fish water to get acid and some times it is salted. Lower than 7.0 Ph. the 304 will corrode and rust through, because of the salt and or the acid. When I was doing Instrument Tech work we used a lot of 316 stainless in acid service or salt service. OH also I bet you could use PEX tubing like they use in the floor heating systems called Hydronic Heating. It transfers heat and must be pretty temp resistant or it would not be used in Hydronics, and it is quite flexible and inexpensive. If I remember right 3/4" was about $0.60 a foot.

Third is the Thermo siphoning effect. The reason it seems to work when it should not is because of the heat. It would seem that the water in the system would be in balance but it is not. The water in the heater side is being heated which makes it lighter and will rise because of the heat. Even when the header tank is hot the collector just keeps on collecting the heat and the hot water pushes up and finally overcomes the outlet and pushes it out. The collector makes more and more pressure till it moves the water, continuously till you remove the heat. Water movement causes a suction that pulls in more from the tank to be heated. Granted it is not much pressure but it does not take much.

Summer winter change over is simply a standard adaption of the passive solar principle. In hot summer the sun shines straight down. In Winter the sun shines at an angle even at midday. So you build a roof over the solar collector to shade it from the Summer sunshine and let the Winter sunshine in. You have to figure out what angle to set up the collector in the first place to get the most solar energy on your collector surface. That changes for your distance from the equator. Looks like you have used about 45 degrees elevation angle in your testing. Next decide where the sun will be when the temps start to average high enough to stop heating with the sun. That will be the angle that you will set the roof line to shade the collector or most of it anyway. Enough to stop heating the water. Azimuth angle is the sweep left and right. Elevation is the angle up from horizontal.For me in Arkansas it is about 43 degrees elevation for mid winter. Then you need to figure out the time you get sun and I think you stated already about 8 to 5 or so for effective collection. The middle of that is 12:30. What ever that angle is is where you set the collector for ideal heat collection. My Azimuth angle is 210 degrees last time I figured it out. You might need to change to three different times during the winter where you are. Here one is enough. EEHHHHH I bet you already know that don't you.

I wish I could write what I think in clear words and phrases and get it on paper the first try. Hope that last post is not too hard to understand.

There is a website I think that you can input your location and it will give you a range of relevent angles. I was interested in verandah angles and overhangs and the sort for building a thermal efficient house. I still felt like some professional guidanced was called for after playing with it for a while but I got the gist. Luckily I have no money to build a house with so I never had to do the math.

Was there ever a commercial product developed out of this? if so how much and what were the final specs?

The manufacturer that was backing me at the time... withdrew.... mainly because the freight companies jsut kept destroying the evac tubes in transit... and he wasn't prepared to gaurantee that he could ship the units around...

Plus I burnt out the controller unit......

I continued to run it up until I recently moved.... just on a timer... and an aquaponics sequencing valve...

I hate stories with a sad ending!

I just found the thread and I was getting more and more excited as it went along!

I have 30 evacuated tubes up on my roof and the 350 litre hot water tank regularly gets up to 73C so I was hoping this would be viable!

I am glad you did the experimentation, sounds like a lot of time and money spent on research and development with no product at the end.

If the only downside to the kit is the damage to the evacuated tubes then that is not such a great problem, I can buy them locally. They even sell the tubes on eBay.

I would be interested in getting the set up even if it isn't in a kit form, I have read the full 12 pages and it looks like there is enough information in there to get something up and running.

Was it close enough t completion that you would try it again?

Absolutely....

Hi folks, I'm looking for exactly this kind of kit!
I have some warm water fish I don't want to get rid of, and also can't bare the slow growth for 8+ months a year in the cold Melbourne climate. Greenhouse helps but still need more heat.
I know someone who is using evacuated glass tube system to heat their aquaponics system, and I found a local distributor, but have no idea how large/how many tubes I would need for my small 600L IBC system. I will have 3 more 600L tanks which are empty, just supporting the growbeds at the moment, so could utilise them if necessary to prevent sudden temperature changes..
I have interest free finance available, but several solar dealers I have called have no idea what I mean.
If only I knew exactly what to ask for, I could order one immediately.
Many solar dealers don't distinguish between the evacuated glass with copper. Is there a name for the stainless steel ones?


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