Heating of fish tanks in winter has been an issue ever since we started this forum and before. Lots of us have tried all sorts of ways to do it in an economical way.
Mickey has gone with thermostatically controlled electric down there in Melbourne.
I have a client at Kooralbyn who has installed a large Aquaculture type electric heater to heat our 2 x 2300 ltr parabolic tanks and 9 grow beds. He has it hard wired by an electrician and has gone onto tarrif 33 I think.
The low cost tariff that runs from 10pm till 6 am or thereabouts. He says it is holding the water temp at 22 deg really well, Jades are feeding like little pigs and doing well. It has cost him around 70.00 in power bills to keep the water at that temp since the beginning of autumn.
Dave McP has just completed a solar water heater, I hope Dave will give us a run down on how it is going.
Last winter I used el-cheppo 300 watt aquarium heaters in each tank and ended up with a power bill even K Rudd's wife would have trouble paying..
My latest and greatest scheme is to use LPG.
I have purchased off eBay a $200.00 instant hot water system. Supposed to produce 6 lpm of hot water...only does 3 lpm
I have also purchased a thermostatically controlled aquarium heater. I wanted the control not the heater, because the controller is external to the tank and looks simple but good.
I already have an assortment of pumps laying around the shed.
I have a roll of 19mm soft wall irrigation black poly pipe
I have numerous fittings.
The PLAN - ... I will attempt to use a thermostat to control the switching of a pump that will in turn activate the instant hot water gas system and the heated water will be pumped from a 200 lrt holding tank through the Gas HWS then through the soft poly pipe that is emmersed in the sump of the DUO system. The heat transfur will take place in the sump and the heated sump water will be pumped as per usual to the fish tank.
When the thermostat probe that is in the outlet of the fish tank detects 20 deg C the thermostat will switch the pump off which in turn will stop the Gas HWS. When the probe detects 18 deg C the pump will be switched on and so on and so on.
The thermostat will be set to a temp range of 18 to 20 deg C. I have since discovered, to my delight, that this low cost 18.00 plus post thermostat is actually able to keep in a 2 deg range. I have it set to 18 deg on and 20 deg off.
Yesterday I put together the trial system and gave it a run.
Found that the little Gas HWS took a lot of fiddleing to get it to work...has all sorts of safety cut outs that are impossible to work out from the very well written china instructions.
The water temp in the DUO system was at 16 deg. After 6 hours of running off a timer 17 minutes on and 5 minutes off the entire system water temp had risen to 25 deg. We had to run the switching regime because we discovered that one of the safety cut outs on the Gas HWS is that it automatically switched itself off at 20 minutes.
Tonight I will be running it off the thermostat which , when, and if, the water temp drops to just below 18 deg the thermostat will switch on the pump via a analogue timer set to 15 minutes off and 15 minutes on.
That sequence will continue until system temp is 20 deg, then the thermostat will switch the pump off.
At dark today the system temp was 23.9 deg
The greenhouse temp was 20 deg (it had peaked at 34 deg in the greenhouse during the day)
Why am I doing all this....I hate using the mains power...we are being ripped off at an astonishing rate on that one, thanks to the government of the people for Macquarie bank by the faceless bureaucrats.
I am guessing Gas will be much less expensive to use doing a fairly efficient job..
So we will see how well it goes. Any comments ????
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Originally Posted by GaryD
