Backyard Aquaponics
A place to discuss aquaponics

I was thinking I would have to prefilter the water to not clog the small tubes. Has anyone done this and what type of plumbing would I need. A few concerns: temps too hot coming in to sump, being able to keep temp in system regulated(the need for a thermostat), and any issues with large temp differences in sump where I also have some tilapia.

I have also thought about using something like this but only if needed.

I was thinking of using a pool solar panel as well. you would need to plumb with a bypass value like the pool uses so you can control the temp by how much of your water goes up to the panel . also make sure you close it at night or it will COOL your fish tank water

I've considered this as well but don't have a good location to put one yet. The longest wall I have available is shorter than the shortest pool heater I could find . Some information might be available on http://www.BuilditSolar.com

locate them on your southern facing roof

Rupe did a solar array experiment

viewtopic.php?f=8&t=3976&hilit=heat

Thanks, I may eventually get to this point but I'm hoping to add this to the back wall of the greenhouse so it gets a boost from being inside. Only problem is the greenhouse isn't up. I'm not sure how well this will work (it might get warmer on the roof) but that's the plan for the moment.

The experience of using a few black poly pipe coils to warm my FT's in winter taught me a couple of lessons last year.

I definitely needed to clean out the pipes every couple of weeks as the fish waste and bio matter built up quickly and reduced the flow of water.

I would recommend you add a click on hose fitting at one end to assist with the flushing out of the pipes and don't flush it back into your system.

If you use 2 water loops with 2 pumps - one loop for your roof that is clean, and one from the tank that may be dirty - you can prevent blockage of your solar panels. You will need a heat exchanger in between, a tube in tube type is quite easy to make with a PVC tube and SS316 tubes. In parts of the northern hemishere all solar systems have this system, as they have glycol in the roof solar circuit to prevent freezing in winter and transfer the heat to the potable water via indirect heat transfer.

Im actually into heat exchangers for a living, sounds like a good challenge!

Hi Guys
I am looking at solar heating ideas for my system, Has anyone tried using 12mm or 19mm polypipe?
I am thinking of using the natural rise of hot water, as water heats up it becomes lighter than cold water rising to the top of the FT then a connection to the bottom of the FT draws the cold water into the poly pipe which is in the sun.
The poly pipe is looped from the ground in a continuous rise to the top of the FT thus doing away with a pump.
The only thing is, it will need a controller to close a valve when the water gets to the required temp.
I've used this set up with swimming pool solar panels the only difference is the controller turns on the pump to circulate the water where I want it to turn on an electric valve. Maybe one similar to an automated sprinkler system.
Any thoughts?

I use a 100m of 19mm pipe it feeds of my pump in the sump does a lap around and back into the sump , some days its very effective other days cold wind seems to reduce the effect .

A mate came up with an idea to run it out the top of our fish tanks via a bulkhead fitting around the garden and dump it in the sump (all by gravity) so im going to give that a try very little fish waste in the top couple of inches of the fish tank (less buildup in pipe).

I just have a tap on my line no timers just turn it on in the morning and off at night , also running constant flood at night will lessen the cooling effect , if its a bit warmer day I only open the tap halfway wont take you long to get the hang of how it effects your system .

Im going to enclose my pipe somehow to lessen the cold wind effect maybe a shuttle covered with polycarbonate with the pipe coiled inside (mini greenhouse) or similar . It frustrates me when my silvers just look at the feed I put in they will eat lettuce and worms when the waters pretty cold but not much .

I'm not sure about heating water, but I know you can drape pool covers over your greenhouse to hold in heat.

Instead of using a heat exchanger for Rupe's idea, you could try a closed loop system that does not use fish water at all.

All you need to do is run the piping through the evac tubes and then through another pipe that is laid on the floor of the FT. this will then exchange heat with the FT without using any dirty fish water.

You would have to have a fair amount of piping at the bottom of the FT though so that the heat can transfer to the fish water.

You could also use copper heat exchangers then (which was the main inefficiency in the first model) as the heated water would never come into contact with the fish water.

Just a thought.

Friendly Aquaponics does a lot with solar water heating. They might have some ideas, though they'd probably charge for the reading material.

I remember reading that vermiculite does a great job holding heat. I wonder how well a heat exchanger with water saturated vermiculite would stabilize temperatures. It would be a two loop system, copper in the solar collector, black pex in the AP side. Propylene glycol added to the solar side to prevent freezing in climates that need it. The solar pump running on a solar panel without a battery, so it automatically turns off when there is no sun. It would not be instant gratification, as it would take some time to "charge" the vermiculite, but once it is charged, I think temp fluctuations would be greatly reduced.