Backyard Aquaponics
A place to discuss aquaponics

Two days temp readings.
Vertical line on the left is 'cos I had to turn the PC off for a bit.
The black pipe just laid on the ground appears to have raised the average temp by about 2C-3C, which for 300Baht (about $10) is pretty good I reckon.

@sterfire
Yeah I've seen that site before, some good DIY examples there.
I may try something like that if I get time.

I've been thinking about the solar heating setup... and was wondering how having a separate resevoir that gets heated by the solar WH would go if a pump was used to to pump water into the main FT with a thermostatically controlled pump... I keep getting stuck on the fact that the pump would have to be in the hot water (unless you could make some kind of a closed loop system), and I don't think it would be able to handle that for long...

Has anyone experimented with the pex pipe in these types of setups yet to get around the leaching issues black polypipe and copper pipes have?

PEX pipe is used for the hot water lines in your house, for some solar heating setups that would be fine, but over 120F unsure...

Yes, the red PEX pipe is rated to something like 90 degrees Celcius with a safety margin of around 120 degrees C and is being used because apparently it doesn't leach chems into the water. I'm not sure how good it would be at heating water though. From memory it is made from something like alternate layers of polyethyene and a metal like aluminium or zinc and it's meant to be quite insulated so it might not heat water up enough to do the trick. Maybe spray-painting it black might help The places I've looked at here in Australia that stock PEX pipe say that it works out cheaper than copper pipe for plumbing a house without the added risk of copper dissolving into the water. I don't think joining it is as straight forward as polypipe, PVC, or copper though with special tools required for the job.

Just had an idea while thinking bout hownto heat the future FT if need be: how about laying a few flat stones out on the ground in direct sunlight for thewhole day and then chucking them in the sump at nightfall? They should release heat slowly.
The same goes for soda bottles that have been sitting under the sun the whole day, seeing as it's more of a question of maintaining a certain temperature rather than downright achieving it.

TBH I don't think a few stones would make much difference, unless you had a really small system.
It takes a lot of energy (relatively) to heat water.
Insulation of some sort would be more effective to maintain temperatures.
I had a load of polystyrene plates that I put on the surface of the water at night when it was getting down to 10 degrees or so, that seemed to work really well.

After posting that I actually looked into DIY solar water heaters (using plastic bottles and pvc pipe) maybe work with one of those?
What about natural insulation? My ivy and jasmine grow like mad: what if one planted some cuttings around the FT and let those crawl and climb around the FT?
I read some where that people who let ivy grow over the house keep the heat out in the summer and inside during winter.

All I use is PEX, all that is needed is a tool that looks like a big set of pliars. We can buy them for about 20 bucks. Or a complete set for about 50 dollars. One of the nicest things about pex is that you can remove the tube from the connectors and reuse the connections. I hate PVC pipe now, but still have to use if for drains and such on the aquaponics system.

I have cut up black (poly?) pipe in my systems. I have seen pretty large tilapia backyard farming ops using it to heat their water up. They have huge coils of it. I have cut up black pipe as a filter media in my blue barrel filter and shade net bags of it in my sumps for extra filtration. People use it to irrigate food crops. Exactly how dangerous is this leaching issue? I have documented using it as a filter media in my posts and nobody said, hey, don't use that stuff, it's poisonous.

I have been contemplating creating a solar heater for my tilapia from the stuff for some time but now I am thinking I should be removing it from all my systems. Apparently pvc also has issues but we all use it.. Exactly what are we supposed to use? If poly pipe is dangerous then my water supply is poisoned as it is pumped through a poly pipe from the well point. A local guy made a solar collector panel using pvc which he painted black in a polycarbonate covered box.. Perhaps that is the way to go here.

Or make a sort of shallow bag using pond liner up on the roof? Sort of like a hot water bottle that you pump water through. Liner is probably also not safe Are blue barrels even safe? Is any plastic really safe to use?

If its the one I saw the collector melted. From what I understand some plastics only leech when they reach a particular temperature.

What melted? The polycarbonate cover or the pvc pipes? The limited amount of reading I've done on this suggests that white PVC pipe painted black may not release chemicals when heated as they are a form rigid PVC (uPVC) to which plasticisers have not been added (see http://en.wikipedia.org/wiki/Pvc ). I don't know how hot they can get before they fail though. Glass would be better than polycarbonate as a cover. Some PVC can contain heavy metals like lead and cadmium too which are used as heat stabilisers.

I like the idea of the poly pipe very much (even not for Tilapia, as a general idea.)
I'd like to bring something up again though... How do you keep all this heated water from loosing heat during the night?

Ahh... the million dollar question...

Hah - I bet even if I had 1 million dollars nobody could answer that.


Some food for thought: some poeple use old tires for growing potatoes for the reasons of being easily stackable one above the other (so you can add volume as your plant grows) but also because they cumulate heat and do a sort of slow-release during the evening hours.
Maybe a round and smaller (diameter-wise) tank that could fit into the largest size of old tires? (huge truck/tractor tires)