The Heating Connundrum

[Carson McKenna]

As far as Aquaponics goes, I have a question that's been plaguing me since I first learned of the whole "fish-plant" symbiosis. It's very silly, and I only dare ask it among you, my fellow AP neophytes.

My problem is this: even after reading Sylvia's book, scrolling through posts on fish sweaters, furnace heating, and the like, I STILL fail to understand heating in Aquaponics!

Let's say I want to raise cats (meow). Fine, I put about 20 in a 150 gallon IBC, knowledgable in what temps these whiskered bad-boys need to grow into strapping, one-pounder dinners someday (25-27 degrees C, or 77-82 degrees F). What I don't understand is how to create and contain that temperature in the tanks, consistently throughout the day/night.

There are a lot of discussions on here about different kinds of heating sources. While I love the sound of a wood furnace in a contained but ventilated area, it doesn't seem to me that this would be enough to heat the water to the necessary temperatures. To me it seems that the water itself needs a continual heat source. An ancillary such as a fish sweater seems wholly necessary. Even inevitable.

Can anyone weigh in here on how they keep their water warm enough for their fish to grow and be healthy?

Thank you all!
Carson

[Leo White Bear]

Carson-

  There are many You Tube videos on the Net that walk you through making a heater out of a water heater element and some PVC pipe.  They are also regulated with a Spa thermostate to keep them from running constantly.  Google "Aquaponic Fish Tank Heater" and many various heater configuration builds will pop up.  Most of these are in You Tube so be prepared to watch quite a few.

[Vlad Jovanovic]

I definitely agree with Rob on this one. In your 'basement' situation, your probably much better off just insulating the tanks and heating the air not the water. When your water temps are warmer than your air temps, your can look forward to lots of condensation and the veritable plethoric cornucopia of problems that , that bring with it (both to your plants and to your building).

IMO forgo the expensive and unimpressive LED lighting and use HID's...They are still the cheapest most effective lighting solution for growing plants...They'll definitely help both heat the air, as well as help to dry the air (you still may need to throw in a de-humidifier down there to help with all that moisture)...

Man, I really need to change my avatar...nice response time guys. I think this is a record breaker 

Rob Torcellini said:

If you're running the system in your basement, I probably wouldn't heat the water too much..if any.  You're going to have high humidity in the basement and will increase the risk of mold/mildew in your house.    The cold foundation walls during the winter will condensate a lot.  Normally, I would agree with Rick, but this is one of the rare cases where I would say you should heat the air instead of the water, even though it isn't very efficient way of heating the water.  A lot of this depends on how much air flow you have going through your basement.

[Carson McKenna]

Rob,

Thanks for your input. You have got me thinking about air flow now. Hardly anybody goes down there, so with the exception of me breezing about, tending to the system, I can keep air flow to a minimum. Is that better for keeping the air temps level?



Rob Torcellini said:

If you're running the system in your basement, I probably wouldn't heat the water too much..if any.  You're going to have high humidity in the basement and will increase the risk of mold/mildew in your house.    The cold foundation walls during the winter will condensate a lot.  Normally, I would agree with Rick, but this is one of the rare cases where I would say you should heat the air instead of the water, even though it isn't very efficient way of heating the water.  A lot of this depends on how much air flow you have going through your basement.

[Carson McKenna]

Robert,

I think Geodesic domes have a lot of appeal. Keep us all abreast of how the construction goes.

Where do you think the FT size starts to make a real improvement in temperature variations? 300 gallons, more?




Robert Rowe said:

Carson

First understand that the water temperature will try to follow the Oatside Temperature (OAT), but it can't catch up, resulting in your water tending to settle in at the mean temp, or the average of the high and low temps gives a good approximation.

The size of your tank is a factor. a larger mass will minimize the temp. variation.

 My scheme is to take advantage of any solar heat during the day to get to the target temp. At night when power is cheap at least on my service, I have some 300 watt aquarium heaters to help hold the temperature up.

I also have my main FT inside of a 10' Dia Geodesic dome which is insulated to R13. This is under construction now. I am in the process of installing the insulation.

The main thing is to do what you can passively first then go to power as required.

Don't wait till fall to work this out or you will end up with a house full of aquariums as winter lodging for your fish.

[Rob Torcellini]

you actually want to increase the air flow to reduce the humidity.  I would install an air exchanger or at least a dehumidifier.

Carson McKenna said:

Rob,

Thanks for your input. You have got me thinking about air flow now. Hardly anybody goes down there, so with the exception of me breezing about, tending to the system, I can keep air flow to a minimum. Is that better for keeping the air temps level?



Rob Torcellini said:

If you're running the system in your basement, I probably wouldn't heat the water too much..if any.  You're going to have high humidity in the basement and will increase the risk of mold/mildew in your house.    The cold foundation walls during the winter will condensate a lot.  Normally, I would agree with Rick, but this is one of the rare cases where I would say you should heat the air instead of the water, even though it isn't very efficient way of heating the water.  A lot of this depends on how much air flow you have going through your basement.

[Carson McKenna]

Vlad, don't be hard on yourself. It was a late post, 10:15 for us in Europe. (I think I've got the wrong time zone down, the post read 10:15 am instead of pm) You're not losing your touch!

I have read a few of your posts that discuss the merits of HIDs. I will have to go back and re-read some (hopefully it isn't hard to search old topics with keywords on these forums).

But since I have you here, I would love to hear what role HID lights play in your own system. Do you use them as a substitute for the sun, during winter, etc.? My friend and I talked about indoor lighting, and he worries that growing your plants under surrogate lighting will compromise the quality of the vegetable. Do you have any thoughts on this? :)


Vlad Jovanovic said:

I definitely agree with Rob on this one. In your 'basement' situation, your probably much better off just insulating the tanks and heating the air not the water. When your water temps are warmer than your air temps, your can look forward to lots of condensation and the veritable plethoric cornucopia of problems that , that bring with it (both to your plants and to your building).

IMO forgo the expensive and unimpressive LED lighting and use HID's...They are still the cheapest most effective lighting solution for growing plants...They'll definitely help both heat the air, as well as help to dry the air (you still may need to throw in a de-humidifier down there to help with all that moisture)...

Man, I really need to change my avatar...nice response time guys. I think this is a record breaker 

Rob Torcellini said:

If you're running the system in your basement, I probably wouldn't heat the water too much..if any.  You're going to have high humidity in the basement and will increase the risk of mold/mildew in your house.    The cold foundation walls during the winter will condensate a lot.  Normally, I would agree with Rick, but this is one of the rare cases where I would say you should heat the air instead of the water, even though it isn't very efficient way of heating the water.  A lot of this depends on how much air flow you have going through your basement.

:P :P :D :) :( :P :P

[Robert Rowe]

I can't say at what size the volume would make a big difference but I perceive it would be a straight line increase.

 At 300-500 gallon size cubic container, would be easy to insulate and a removable insulated cover is also practical.

The Geodesic Dome is fun, but I would make it at least a 12 ft diameter.

 Part of the reason for my size is the 10 ft diameter keeps the floor under 100 square ft, which seems to be a key point regarding Building permits. Avoiding a foundation I understand will also help.

Carson McKenna said:

Robert,

I think Geodesic domes have a lot of appeal. Keep us all abreast of how the construction goes.

Where do you think the FT size starts to make a real improvement in temperature variations? 300 gallons, more?




Robert Rowe said:

Carson

First understand that the water temperature will try to follow the Oatside Temperature (OAT), but it can't catch up, resulting in your water tending to settle in at the mean temp, or the average of the high and low temps gives a good approximation.

The size of your tank is a factor. a larger mass will minimize the temp. variation.

 My scheme is to take advantage of any solar heat during the day to get to the target temp. At night when power is cheap at least on my service, I have some 300 watt aquarium heaters to help hold the temperature up.

I also have my main FT inside of a 10' Dia Geodesic dome which is insulated to R13. This is under construction now. I am in the process of installing the insulation.

The main thing is to do what you can passively first then go to power as required.

Don't wait till fall to work this out or you will end up with a house full of aquariums as winter lodging for your fish.

[Vlad Jovanovic]

I've grown plants in windowless basements, attics, bedrooms, grow boxes, sheds, an airplane hanger in Holland, an old military tunnel in the side of a mountain…I’ve used T-8’s, ODNO’d T-8’s, T-5’s, HOT T-5’s, PLL’s (my current personal favorites of the fluoro realm), MH, HPS, old school CMH’s, and thanks to the the very cool, gracious, sexy, yet mysteriously silent as of late, Mr. Jon Parr of Fishnet Aquaponics, a ‘new school’ (soon to be discontinued for a more expensive version by Phillips) CMH bulb, Hotilux, Growlux, and my current personal fave (besides the CMH), the Phillips Son-T-Agro-T Plus…and yes, of course I have thoughts and opinions on each of them …though you know what they say about opinions…but I’ve also got some hardcore reality numbers on many of them as well…A lot of which (of any pertinence anyways) has been posted somewhere or another… strewn about these forum pages…So if there’s something specific you can’t find using the search field…just ask. (None of this makes me any kind of “expert” or “authority” or anything…I’m just a guy who is capable of making some observations, and can add, subtract, multiply and divide…)

To make a long story short HID’s are the cheapest to own, run and operate in the long run…Watt for Watt, lumen for lumen, dollar for dollar. Also, in the summer time, when their heat is not needed,  it is very easy to vent and expel that heat outside of the growing area.

LED’s or induction lighting I have no personal experience with so I can’t really help you there…

If you give your plants enough proper lighting, I don’t think you have anything to worry about as far as ‘quality’ issues are concerned. I’ve not ever submitted my plants to leaf content analysis (because that would be just silly, as there is much published research on the topic already. You can quell your friends worries by using a CMH bulb…which is a full spectrum. Again, the proper type of light in adequate amounts and your good to go. If your friend has access to any reliable studies that show otherwise, I would sincerely be interested in reading them (no sarcasm or anything, really). All I’ve ever been able to come across on the topic amounts to quasi-religious-mystical nonsense…

In the new GH I’m using HID’s to supplement both heat and light in the winter/fall/early spring…and only for sprouts and seedlings, to give them a jump on life before sending them out into the cold dark world of ‘commercial production land’…i.e the DWC troughs). That way, they put on a lot of leaf mass right quickly, and can then better utilize what little winter sun there is.

[Linda Logan]

There is a huge industry in California, the NW and across the country that grow indoors with obviously great results.  I'd check out what the latest is in those forums or grow shops.  Though I know using Metal Halide to Sodium Vapor was the way a few years ago.  Also all the issues of air flow, humidity, etc. are worked out.  I'm sure there is a store near you that could be a wealth of information.

[Jon Parr]

Mysteriously silent because I'm damned busy, Mr. Jovanovic  (I have my commercial GH in escrow!!! And 500 rolls of DuraSkrim on the way, 25,000 rafts, 2600 starter trays, and cases of seeds and boxes and and bags and plugs and...)

So...I use California as my constant source of heat...supplemented in the winter by wood gasification (unlimited free heat, electricity, and biochar)

[Linda Logan]

you go Jon.  Can't wait to hear and see your new operation.  Send pics when you have something.

[Vlad Jovanovic]

"Pics"...Haha...good one Linda...Getting Jon to take (and post) pics is like getting a vampire to eat garlic