Backyard Aquaponics
A place to discuss aquaponics

pee on it that ll keep some heat going.

Hmmm, I guess I'm gonna have to try that out

Measured the temp of the compost again today at 4pm, and it was sitting at just under 40C! nice and toasty indeed!
I also ran about 9m of polly pipe through the larger compost heap and into my system. I purposely used a small pump on the pipe so as to have a slow rate of flow, but there is barely a 1C change in temp... perhaps longer pip (soon there will be more pipe than compost pile )
My system is still sitting at a cool 22C.

Am, waS THAT 1C temp difference between inlet temp and outlet temps of the pipe?

yep, but barely noticeable - loss to the atmosphere will quickly cancell that gain out...

So, it's going in at 22C. It travels in pipe under compost reaching 40C. Comes out 23C. What length pipe? What size pipe, you may want thinner.

Basically it's risen 5% of the heat differential over the length you have.

23C is cold??

for the barramundi it would seem that way , I thought it was warm enough for them...
I am using NeTA garden pol - 13mm , and there is about 12 m running through the one compost system, and 8m running through the other... I thought that if I slowed the water flow down it may heat up better

I was thinking of placing a largeish metal drum in the mulch, so that that water is heated by the mulch, then unwiding a full 20m coil of polly pipe in it and then connect that to my my ponds - think that might work?

Ol bit of a discussion is going to follow this comment for sure ...........)

If anything, i would increase the length of the pipe even loop it round a few times.

Although slowing the water flow is going to give you a higher outlet temperature the energy / per hour will be the same. i don't think that slowing the water flow so that you get a 10C Td (temp. diff.) will really help. Better to keep the flow rate the same and increase the piple length considerably.

Look at it this way. velocity = 10 and Td = 1C energy put into the system is 1x10=10 (arbitary units)

Velocity = 1 and Td = 10C eneergy put into the system = 10

or, increase the pipe length so with the same velocity you get a 10C Td and 10x10=100 energy put into system.

poly shouyld be good, and it will be out of the UV, and less than 60C so let us know how it turns out

I will have to increase the compost heap size first, then connect more polly pipe... which means waiting a day or so for the heat to build up

Compost temp stable at 41C... no improvement in water temp or the temp of water passing through the compost heaps
I increased the compost size by 20 cm all arounsd, then lengthened it by 1.5 m ... I then went and mowed the entire yard for grass clippings to add to the system (wife thought that I was just wanting to make the yard look nice etc ), and added them to the pile too, then soaked the pile to ensure bacterial action... this reduced heap temp, but it should pick up againg in the next day or 2.

Just measured the compost temp again - it is still at 41C... I placed a water filled tin into the compost this morning and 6 hours later it is also at 41C... My system is holding at 21.5C... which is good as Barra prefer the 20C to 28C range.

I love what your doing AM..........

Thanks EB

OK, a .5 drop there in system but stable now. If you check your ground temperatures over the same period (weather service should have it, farmers weather will) and see if they dropped further you would have a point of reference to see how it's going.

why dont I just use my post hole digger and drop a hole 1 m down myself - and read the temps each day when I do the compost heap's temp...