Backyard Aquaponics
A place to discuss aquaponics

DuiNui-and others

Can you talk more about the data logger and sensor(s). Was it that diode thinggy?

Also please go thru the entire process from the logger to generating the various graphs?

I'm using a different processor and sensor so maybe I could easily translate your pseudo code or your flow chart of your processes and your schematic.

I just might try tilapia because I'll have a wood furnace and or solar collectors (fin tube design) to use.

I'm thinking of putting the panels(with out a ever glazing) on the vertical wall of a lean to GH.

The heat source (furnace or collector water) would be in a closed loop in the FT and possibly under the GBs some way.

I'm trying to figure out what kind of pattern of tubing should go under the BGs.

I'm wide open for suggestions!

It takes a lot of energy to heat water (4.2J to raise 1ml of water by 1 degree) but on the flip side it also takes a long time to cool down. This is why water filled containers are often used as thermal mass in passive solar greenhouses. I think if you were to have a big enough body of water it would have enough thermal stability to maintain temperatures above the minimum required. If you combine this with insulation and an insulated swimming pool cover I reckon you could slow it down even more.

Yeah... like a lake perhaps....

Seriously, while the larger body of water may have better thermal mass... the larger the surface area, particularly if outside... is soon cooled by any wind action....

Getting the heat into the water during the day isn't a problem... keeping it there at night is...

Yes you can keep the average daily temp a little higher than it might be without heating... but not a lot...

Bob, sorry for the late reply I've been away for a while.
I had some trouble calibrating the diode based sensor because I had 3 thermometers all which disagreed with one another, so I bought some LM35's.
The PIC just reads those, stores a 16 bit value for air and water into I2C eeprom, then on demand dumps them from its serial port as a .csv file.
Import to Excel/Open Office and make the graph.
I do have a VB application to do the same, but it's just so much easier to save the file to disk and use Oo.

The code is really simple, read the ADC, multiply by a calibration factor, and store the number, that's it really.
The Sensor in the water was a plastic bottle top filled with molten wax to water proof it.
Still working now, so seems like job's a good'un