Backyard Aquaponics
A place to discuss aquaponics

I live in a cold climate and was planning on building some solar panels to use as a heat source. From studying the active solar systems at builditsolar dot com, I'm thinking about 50 or 60 sf of solar panels, a couple of 55 gal drums as the heat storage and using 1/2 PEX tubing to heat the FT by running it inside the tank in a coil and also coils under the growbeds. When cycling, would it be better to have higher temps?

Hi and welcome to the forum

I dont know anything about solar stuff sorry.

In regards to cycling, yes it is better to have warmer temps. Low temps slow down the nitrification process.

[quote="sunbelt57"]I live in a cold climate and was planning on building some solar panels to use as a heat source. From studying the active solar systems at builditsolar dot com, I'm thinking about 50 or 60 sf of solar panels, a couple of 55 gal drums as the heat storage and using 1/2 PEX tubing to heat the FT by running it inside the tank in a coil and also coils under the growbeds. When cycling, would it be better to have higher temps?[/quo

hey sunbelt,

i am doing the same thing right now. my temps will never get as low as yours but i also wanted to expedite the cycling process as well as maintain a more constant year round temp.

what i have done and am doing:

built a box out of 2x12 material that is 93"x37"x12" on the inside and has a painted osb bottom. inside the box is completely insulated with fiberglass insulation on the sides and bottom. the insulation was then covered with aluminum flashing and painted black - essentially a painted black oven box. sealed with heat resistant caulk. my neighbor had a brand new but discarded triple pained sliding glass door - hence the original box dimensions. i sealed the door into the box to create the heating chamber.

using 3/4' pex tubing i made a ten parallel lines running the length of the door. the entire course is made of only tees and tubing. i tried making a picture but can't get it to fit this forums requirements.

have not installed the system but the box gets hot as hell. i will install it just outside of the greenhouse by the sump tanks - see my system thread:
viewtopic.php?f=18&t=13774&e=0

cheers

Hey dc... I might be showing my iggerance here, but what is pex? I've been looking into setting up something similar to try to keep my FT warm during winter. Most people in Victoria simply swap species but I have a hankering for barramundi and Murray cod, both of which like warm water.

I keep getting warned off it but I have a greenhouse, I can insulate at least one IBC and if I get my wishes, should be able to set up a 400W solar system to power pumps and heater - so if I can use a heat box like you describe as part of the system, if the IBC doesn't lose too much, if I can switch away from the GB's and sump to an insulated MBB filter at night and have (say) a 200W heater in the IBC it should be a low cost system for keeping water to the temperature I need.

Mind you all that is a bit in the future - if I can get it set up for next summer the fish will get time to get a bit of size before the weather cools again.

PEX is a newer piping system with a different plastic than PVC. Instead of glueing it you use crimp rings put on with a special tool.

Here in the southern USA it has been replacing PVC for pressure pipe in new construction. (PVC still used for DWV/drains/septic though).

Edit: Since all the connectors to connect pieces of PEX together are made of metal, probably not much of a place for it for carrying AP water. A coil of PEX for heating should be fine though, as long as no connectors are in the AP water.

You'd be lucky to run the 200w heater.. and pumps.. through the night... on a 400w solar system...

I tried Barra in a 1000L tank... in a garage... with 3 x 300w Jaeger heaters... and could barely keep the temps above 21-22.....

sunbelt
Is your system indoors or in a greenhouse ?
I'm guessing Wyoming - it aint outside.
I use a solar heater in my greenhouse.
You can also use cpvc instead of pex. Cpvc can be heated with a hot air gun and bent around a wooden form to make angles.
Solar is fine if you have designed it right but you will need a backup heat system for when the sun doesn't shine.
Fish aren't too hip on large temp swings.
You could also go with a cooler temp fish but I don't know of any that can beat the growth rate/food conversion rate of Tilapia (but they require warm water).
Also insulate the tank, grow beds and if your system has solar light use layers of plastic with an air space to create more insulation yet allow light in.
If you can burn wood then make a simple wood fired water heater.
jim

And a bloody big thermos of coffee.. to keep you awake all night.. to stoke the wood fired heater...

Worst possible way to produce heat! If you use Lead-acid batteries for storage, only about 85% of the energy is available to use, and if you use an inverter to convert it to 230V thats another loss at ~85% efficiency, for a high quality inverter- and much less for cheap Chinese jobs. Resonable quality PV panels run at 12-15% efficiency at best, with much less output when the sun is not face-on.

Evacuated tubes directly heating the water are going to be at least 6-8 times more efficient, ie you'd probably need 6-8 times the area of PV cf evac tubes for the same amount of heating.

I recently was told about a system in my area (hoping to track them down on the weekend) that uses a waste oil burner to heat the FT. From my understanding he has the unit rigged up with a dripper system so a regular feed of waste oil keeps the burner going. The burner has a stainless coil that heats the water. Waste oil is ubundant in the goldfields so it would cost absolutely nothing to run. I need to see it and have a look how it is all set up. Anyone heard of this type of system?

I dont know of anyone doing it, but you have exactly described the method i was going to use to try and heat my water when i get a more stable living arrangement.

Im inside your mind rsevs