Backyard Aquaponics
A place to discuss aquaponics

Also, would it be more efficient to use an electric or gas booster to supplement the solar heater compared to an aquarium heater to maintain a minimum temperature?


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I'm pretty sure most, if not all, evacuated tubes, other than the water filled ones, will have Copper bulbs or other fittings that plug into the tanks, but whether there is any exposed Cu inside the stainless steel tanks I dont really know- but I would expect there would be, as it is a much better heat conductor than stainless steel.

You can still use water that has contact with Cu by using a heat exchanger that uses Titanium or Stainless on the side in contact with the AP water, or circulate the hot water through coils of stainless steel pipe in the GBs or FT.

Electric heating is more efficient than gas- close to all the heat can be kept in the water, but gas flames waste a lot of heat to the atmosphere. Solar powered heating is much more environmentally sound than gas powered heating too, and if it is town gas, it only encourages more CSG extraction

Just FYI there is already a aquaponic heating system called aquaheat that is a gas or propane offgrid unit. Saw it the other day on facebook.

Edit: heres a link http://theaquaponicsource.com/shop/buil ... -system-2/

Another form of heating your FT. It still comes down to a lot of work keeping your entire system in a controlled environment.

You'll spend more on your heating system than your AP system cost. At the end of the day you have to face the reality that keeping fish to suit your climate is the way to go. Many people start by using a variety of methods to keep the temperature up or down to suit a particular fish species but usually these only last for a season or two before people come back to the fish that suit the local temperatures.

Aside from the initial outlay, using thermosiphoning, a solar heater could potentially cost nothing to run, but provide improved growth rates for fish and plants since fish will eat more, and the microbes also flourish above 18°.

Even using a timer and small pump, I strongly suspect that the solar system will not only pay for itself in one season versus other heating methods, it will also continue to provide additional value any time the weather is below 18° and the sun is out. Which is frequently in Melbourne...

I am using local native fish, but want to increase food production in my limited backyard space.

I know stainless steel evacuated glass tube systems exist that do exactly what I want, but no-one seems to know the brand/model without the copper inside. I have been offered one by a fellow aquaponics enthusiast at a good price, however don't have the cash spare, and can't use my available interest free credit to pay them as I could a solar dealer...


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You could always just buy the evacuated tubes and install the inserts yourself they are two piece units, the glass tube and the element which is fixed onto the stopper from what I can gather.

Continuum, I think you're into something. I just spoke with a manufacturer. They have been telling me I can't get a system without copper. But that was based on them selling complete units, already assembled.
They said they can manufacture one without the copper heat exchanger, or for extra cost, with a stainless steel exchanger. BINGO!

A few details to work out, but it's looking hopeful...


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Glad to be of some help


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+1


more money , more worries, more risk, I comprehend having to learn for yourself, I had to try it myself too. But if you are one of the few smart people in this world that likes to learn from others mistakes and experience... native fish 100% all the way.

What you also seem to be forgetting is that the most effective solar heater you can have is a greenhouse.

There is only so much energy coming from the sun at any one point in time. Greenhouses are very good at capturing that energy and getting it into the system. For a heating system to work it also has to be combined with a way of insulating the system over night (blankets, screens, etc).

To have a solar heating system you will need to collect more energy than you already would be in your greenhouse. Evacuated tubes will allow you to heat water to a higher temperature but unless you combine this with a hot water storage system and a control system to gradually let the heat out into your system over night it is not going to work.

Also get people to tell you how much the temperature of their system goes up during the day in winter. If they have a 20m2 greenhouse how many m2 of evacuated tubes are you going to need to be able to capture the same amount of energy to be stored to be release over night?

May be just may bee there is a better way
My mate who bought in and sold as a business some 7 to 8000Vac tube solar hot water services
[He probably bought in the tubes rupt had ]is now bringing in pellet fed super efficient boilers and selling for heating houses , pools, commercial glasshouses ,
Also I know murray was using a small instant gas hot water system to top up one of his systems
Gas is only dear if you pay full price but that is another story

There are definitely ways it can be done but the costs are pretty serious.

For a serious operation that is not a problem but for a backyard operation...

I am using hardy native fish for my area (silver perch), but I am considering more than just fish survival. Reduced feeding in cold water equals reduced nutrient output, and slow bacteria activity in seasonal temperature changes.

The only logical reason not to invest in heating is if the cost outweighed the rewards.
Sure, it costs $0 not to heat at all, but let's compare the options. Let's say the solar system costs $1,000 and negligible cost to run with thermo-siphoning.
Over the life of the system, presumably several years, the increased production of food and fish should be more than $1,000 compared to the poor output with no heating wouldn't you say?

I am currently paying retail price for vegetables due to slow growth in the cold weather, so imagine the total cost of lost food production for this winter, next winter, year after year. It seems to me that I can't afford NOT to have solar heating!


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First of all is your system in a greenhouse?

If yes what is the current temp difference between your day and night temperatures?

If no build a greenhouse and then get back to us.