Heating options for fish tanks

[Murray]

I have been fiddling around with different methods of heating my 2300 ltr tank trying to find a low cost way of heating.

Firstly I made up a coil of copper pipe and fitted it into a 25 ltr drum filled with water.
Set up a gas burner under that. It worked fine, raised the water temp by 4 deg in a 12 hour period. The down side is that it burnt $20.00 worth of LPG.

I made up a grid of sorts out of 1” black poly pipe and put it up on the shed roof. I managed to raise the temp from 15 deg to 18 deg over the day (3 deg C), but at night the temp dropped back to 15 again.
Last winter I only had a 600 ltr tank so it was easy to cover every night. Making a lid for the big tank is what I will have to do, that is obvious.
I think if I go and get a 100 mtr coil of 3.4” thin walled low pressure irrigation hose and run the water through that up on the shed roof, it should improve. More distance for the water to travel and therefore heat up.

The good part about living in S.E.Qld is that our winters usually have nice sunny warm days around 22 to 25 deg, the bad part is that it hardly ever rains !!!
So the solar hose thing together with a lid on the tank should do the job.

Muzza

[Hamish]

I have been considering buying some cheap land out west so I can live freehold. I love cold crisp sunny days - but dont much care for freezing evenings below zero - and I am sure the plants and fish wouldnt either Although a greenhouse and underground heatsinks would help along with choosing a cooler climate fish - trout.

So looking around at options - if I could secure a source of used cooking oil from a takeaway shop then I was thinking of using one of these to heat the greenhouse and fish water.

http://www.backyardmetalcasting.com/oilburners.html

[fishfood]

Oil heating for green houses is ok if theres no other option the problem is quantity and quality last weekend was talking to a chap down queenscliff who has just changed over to gas at great cost because with oil often you would get 1/2 water cleaning spirits ect ect he said it would take over 10 years to recovercost

[Hamish]

I was thinking of using used cooking oil which if settled and filtered should burn ok in a blast furnace in the links above - these things seem pretty fool proof - they just drip oil into a super heated chamber from what I can gather. Perhaps a hightech approach using jets and pressure to inject atomised oil would be unreliable - but this low tech aproach might be better? And if the vegetable oil is free and the burner can be made from scrap metal then all the better

[Hamish]

Here is some excellent information on how to build a reliable heater to burn used engine oil or vegetable oil. This design aparently solves a lot of the issues that cofront regular oil heaters. This design uses no moving pars, pumps or electric fans - so the only input is the used oil.

http://journeytoforever.org/biofuel_...arth/me11.html

[gavinl]

Hi Murray

Just wondering if your water temperature would remain more constant (or lose less temperature during the night) if you bury 2/3 of your tank - as well as constructing a lid. I've found that my temperature stays constant with the above even though I only use a 900L tank. With the larger tanks, your increased thermal mass should keep the temperature constant longer once heated up during the day - especially when insulated by soil and with a lid.

With such a large tank, perhaps a small excavator, dingo or bobcat would be a good option. Depending on your soil, one hour should nearly do it. Not sure of Brissy prices, but that's about $100 up here. Perhaps a fish and vegie exchange could be arranged for a trade.

Hope it helps

gav

[Murray]

I have found that the lid is the main thing. Most heat loss is via the surface of the water. It is easy enough to wrap the tank with some insulating material if needed. FG does not easily transfer heat so it is a good material in that way.

I do not like the idea of burying the big tank for one reason only. I am a little paranoid about children and bodies of water. Just too easy for a small child to get in with the fish when the tank is buried. I have 6 grand kids and together with all their little mates that descend on us regularly. They are like a hoard of locusts.

The fish tank is a giant kid magnet.

I enjoy watching them enjoy the fish and learning from a very early age that you do get food from a garden....It can be, and is grown at home. (What a novel idea )

It (food) is not produced by some mysterious process in the supermarket.

For me it is a major part of why I do Aquaponics and no-dig gardening. I want my family line to have knowledge on how to provide food for themselves growing up in a very uncertain world. In the very near future it may just make the difference for them.