Backyard Aquaponics
A place to discuss aquaponics

Ah, so we need an open loop design!

or a stainless steel heat exchanger

......or a black poly pipe one.

stainless would work, but I have no idea where you could get some and it would be expensive. Black poly is probably not worth it - too little transfer. corrugated unslotted ag pipe might work.

Yeah coppers a no no. That reminds me - copper will make all your snails leave the water - snail problems anyone?

An old hands trick for saprolegnia was to put copper in the pond till the snails all migrate up then remove the copper.

My 100m coil of beva tube painted black on the roof of my carport with a 50 watt pump pushes 20 degree water out at 35 degs on a good day. I can lift my 2500 litres from 22 degs to 26 degs in 7 or 8 hours for about 5 cents in power.

plastic pipes seems to work well when thery are the solar collector part of the system and system water is pumped though them.

if they had another loop in the tank in a closed loop heating system then they wouldn't work well due to the poor conductivity of the plastic, which is what i assume njh meant.

Otherwise they work fine, monyas having luck, and its pretty much the standard for solar heating in pools too.

I'm not up on the technical stuff like NJH - is he saying that having a coil of stainless in the fish tank as a heat transfer for water being heated from black plastic on the roof will not be effective?

no, i think he means using black poly inside tank would not transfer heat to the water well. which i agree with.

I assume monya is using tank water passed through black poly pipe and back to his tank. it works for him.

i see no reason why the ss heat exchanger in the tank connected to the black poly on the roof won't work if you wish to keep the tank water isolated.

PS, i'm buying myself a TIG for a late christmas pressie.........hello s/s heat exchangers

NJH was suggesting a 40 foot 1/2 inch copper heat exchanger would not work well. Putting aside the issue of copper and fish - I don't understand why 40 foot wouldn't transfer the heat quite well provided the heated water moved through continuously or regulalrly.

I've had my eye on a nice inverter MIG which would weld stainless okay. Can't justify the cost. I think I might be too unco to use a tig - too many things to do at once. I am starting to get a feel for my stick welder - so that will keep me going for the moment.

You have to know how to weld WELL on a mig before you go for the TIG... You have to look after your tips well because at $30 each they are not cheap. They recommend replacing them every so many hours welding but if you be careful you can make them last for ages... Especially for us when we only need to weld once in a blue moon. My gas less MIG has seen better days, but I am not confident enough to move up to TIG yet, plus I don't have three phase. So I'll be getting a CO2 or Argon MIG soon.

i'm just weird.

the first welder i ever learned to use was a TIG, welding 6mm OD tubes with 1mm side walls and fusing .5mm thermocouple wire.

This was before anyone told me it was the hardest to master.................

I went to a my mates place who builds engines and customises bikes and he was usiing his new MIG to build an engine trolley. He passes me the mig and goes "here, finish it"

"Nah, i've never used a mig before" says I

I finnished up the welds, and he goes "you've never used a MIG?"

Apparently the welds were shit hot felt all proud and stuff LOL

Went through TIG withdrawls when i left that job 8 years ago or so. was too easy to bring in what ever i needed to weld.

VB u sure that what he was saying? cause i'm sure that would transfer heat a plenty, otherwise millions of water heat exchangers for HVAC world wide are not working. And they are exchanging to AIR, not water which has a far better thermal conductivity.

Not sure Steve - read it for yourself, its on the previous page. You might understand the terminology better you welding God. Wish I was better at it - the first welding I ever did was my first grow bed stand. I really enjoy doing it, but my technique is probably really dodgy cause I've never watched anybody else weld, or had anybody watch me. Oh and also I do not have a steady hand. Have had the shakes for as long as I can remember. The chicks dig it though

ROFLMAO

VB, i've told you i'm a very visual person..........now that, just before i go to bed.......how am i ever going to sleep

Will try some stuff real soon. am thinking circular coil s/s heat exchanger, maybe 20 cm diameter, maybe 20 loops? just Sooooooooooooo busy!

Man, its just practice, change the way you do it ever now and then till you find the right style for you.