Backyard Aquaponics
A place to discuss aquaponics

Check out this link for the results of a study on greenhousing for the maintenence of water temps in aquaculture.

http://dspace.library.cornell.edu/bitst ... ec2005.pdf

wow, thats alot of equations!!!

interesting.

Here is another that I found interesting:

www.freshwaterinstitute.org/pdf/nat%20g ... manual.pdf

[quote]Quote:iii) For uniform water temperature inside the greenhouse, the tank should be buried in the
ground.quote]

sounds familiar

I guess I need to rethink the tank burial thing!

It' a six of these half dozen of them kind a thing I'd say. It all depends on whats most important to the builder/operator, more thermal stability or ease of tank acess(sp). There are ways around either. I needed in my mind to bury my tank not only for the stability but for the space it takes up. Just have to weigh the pros and cons of your individual system.
That is alot of math!

If and when i do it over, I will not bury the tank unless I absolutely need the space (in which case I will not be doing another system if I can't have the space I need), but rather build (kind of like I have in my system) a sheltered and insulated housing for the tank/s, but more of an actual greenhouse with a fish house attached. I'm curious John to see how you control algae growth in the tank or if you get algae blooms at all...

I like the seperate fish house with attached green house concept. I am looking across the street and planning the next system. We have an old Ice House over there that would be usefull. Sheez, does the AP bug ever get its fill? I can emagine myself homeless pushing a shopping cart and picking up bits and pieces to get a system going! If your just starting folks leave while you still can! LOL

LOL....that's funny...remember Steve Martin in The Jerk? "I've got my pump, my plastic tray, my pvc, my plastic container.....that's all I need."

ROFLMAF, perfect fit MF.
Mevans, nice site on that construction and operating cost. I remember seeing that grow bed heating picture somewhere before. Things get a bit blurry, so much to learn. Thanks for the link!

LOL!!!

The buried tank in that paper looks to be uninsulated. If the tank were insulated it would isolate it from air temp changes, but I think some of the moderating effects were from the increased thermal mass (including the dirt surrounding the tank). My ground temps are 50 degrees, and since I want water to be at 70 and above the tank would be insulated, and the temp swings would still be tied to the water volume. Anyway, the main reason I would bury even a cold water tank is to get to use gravity return on the grow beds.

I think I've read the second link before, because the picture of the grow bed heating tubes rang a bell. I remembered it as "heat tape", which is the electrical wire you put around camper hoses to keep them from freezing in Winter. I have been wondering about using a water bed heating pad under the gravel, rather than using aquarium-style heaters.

It would be interesting to see how much heated beds would maintain the water temps. A radiant floor heat system for your plants, now thats just spoiling them!

I will be burying my tank this weekend for a number of reasons including water temp stability, space saving in the greenhouse and the ability to gravity drain the towers back to the tank. This is probably the most important aspect to me as I see it as a failsafe. If everything goes pear shaped at least the tank will remain as full as possible.

While measuring up the space where I intend sinking it (which is adjacent to a couple of compost bins) I had an idea. If I dig the hole out 500mm wider that the tank I could fill the space with grass clippings and other garden waste.

This may provide insulation and a bit of added heat.

Does this sound feasible?