David R Posted May 7, 2012 Report Share Posted May 7, 2012 Now that my one tank isn't in a nicely insulated fishroom with a fairly constant temperature I've noticed the thermostat on my Jager heater doesn't seem particularly accurate (well, at least IMO) and the tank will fluctuate by about 2-3C. It that with in the acceptable range for a heater? The fish seem fine with it, but is there anything out there I can use to more accurately control the temp of the tank?? Quote Link to comment Share on other sites More sharing options...
Ira Posted May 7, 2012 Report Share Posted May 7, 2012 Now that my one tank isn't in a nicely insulated fishroom with a fairly constant temperature I've noticed the thermostat on my Jager heater doesn't seem particularly accurate (well, at least IMO) and the tank will fluctuate by about 2-3C. It that with in the acceptable range for a heater? The fish seem fine with it, but is there anything out there I can use to more accurately control the temp of the tank?? Like from say 25-27? Yeah, I'd call that acceptable. Better circulation could help. Or good circulation and a good temperature controller might give you better precision. But that's not enough to worry about. Quote Link to comment Share on other sites More sharing options...
David R Posted May 7, 2012 Author Report Share Posted May 7, 2012 Not really worried, just looking for ways to waste money... :lol: Heater is in sump so has plenty of water moving across it, I'm wondering if I should use two 200W instead of one 300W, the 300w does seem to spend a lot of time on. Two heaters would give me more surface area and probably do a better job of heating the sump, unfortunately its too short to run two 300w side by side or I'd just do that as I have a couple spare! (when I get them back from Henward that is!) Quote Link to comment Share on other sites More sharing options...
Ira Posted May 7, 2012 Report Share Posted May 7, 2012 Not really worried, just looking for ways to waste money... :lol: Heater is in sump so has plenty of water moving across it, I'm wondering if I should use two 200W instead of one 300W, the 300w does seem to spend a lot of time on. Two heaters would give me more surface area and probably do a better job of heating the sump, unfortunately its too short to run two 300w side by side or I'd just do that as I have a couple spare! (when I get them back from Henward that is!) You could possibly get a bit more stable temp with the two thermostats rather than one. I'm assuming that's the issue, not lack of power to make up for the heat loss. In which case 2X200s would also help. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 7, 2012 Report Share Posted May 7, 2012 The hysteresis on most aquarium thermostats would give a variation of about 2 degrees so that would be normal. If you run two heaters each with a thermostat chances are only one will operate and the other will be backup. I had thermostats with a hysteresis of 0.1 deg C running under tank heat mats and the temperature variation was more than what you are getting because of the media in the bottom. Keep your money and spend it on more fish one day. Quote Link to comment Share on other sites More sharing options...
David R Posted May 9, 2012 Author Report Share Posted May 9, 2012 So back to my original question (ignoring the fact that a 2c fluctuation isnt anything to worry about and I don't really need it), who makes an accurate thermostat/controller and where can I get one? And on this topic, I just checked the thermometer on my TDS meter in a slurry of ice and it is about 0.8C high, and it looks like the cheapo digital one in the tank is a degree or two too cold, meaning my tank has been more like 30C thank 27-8C. What is out there that is more accurate than the el-cheapo ones but not up in the super-accurate-mega-dollars scientist-accurate range? Or now I know how much to correct the reading by am I better off sticking with the cheap one and learning to add how ever much to the reading? Quote Link to comment Share on other sites More sharing options...
KrazyGeoff Posted May 9, 2012 Report Share Posted May 9, 2012 The cheepo digital ones are cr@p. I buy 5 or so at a time, and can get 10 degrees difference between the warmest and coolest, when measuring the same water. So I have an alcohol based one that I use as my standard and then calibrate each of the digitals, against. But the brand I was using has changed their design and now if they were only cr@p I would be happy. So I got an expensive gadget, which seems accurate enough. One of my tanks runs at 32, so when I say accurate enough, I mean accurate enough! Because this may be real close to boiled fish. Quote Link to comment Share on other sites More sharing options...
hovmoller Posted May 9, 2012 Report Share Posted May 9, 2012 It that with in the acceptable range for a heater? For an eheim I don't think so... does it get very cold in the room? are you using poly? Why don't you give me your tank & sump dims, the temp you want tank at and min temp you think the room will get and I'll run it through my heatloss calc.? Quote Link to comment Share on other sites More sharing options...
David R Posted May 9, 2012 Author Report Share Posted May 9, 2012 Thanks Thomas, tank is 140x65x48 external dimensions (water level from substrate is more like 41cm), sump is 62x40x27 when running. Not using poly other than under the tank, probably could/should but don't think I'll bother. I am going to look at enclosing the stand with MDF/pine panels so the sump will be slightly more insulated. The room temp fluctuates greatly, when I'm on an early shift I'll open the curtains at 4am and the windows are always ajar so it gets pretty chilly, but then in the evenings its just off the lounge and with the curtains shut and fire cranked up the ambient temp is fairly warm. Whats the expensive gadget Geoff and where did you get it? 32C doesn't give you much margin of error, a couple of degrees over that would be trouble! I'm not even sure if you can calibrate the cheapo one I have, I've been logging the temp on it compared to the TDS meter over the past few hours and its only 0.5-0.7C lower than the actual temp (temp on TDS meter -0.8C). Would be nice to have something a bit more accurate though, I'm sure the reefers don't just rely on the heaters thermostat and a $5 digital thermometer! Quote Link to comment Share on other sites More sharing options...
hovmoller Posted May 9, 2012 Report Share Posted May 9, 2012 Ok.. So if the temp in your room were to reach 14dC and your tank is 27dC you would need a theoretical 316Watts (continuous) to keep that temperature in the tank. That is assuming 10mm poly and 12mm ply under both tank and sump. Of course that does not include any added heating from pump, lights, etc. I chose 14dC because that is when your 300W heater will no longer be enough. If you were to put 25mm poly on rear and sides of your tank and on all 4 sides of your sump, your power consumption at that temp difference would drop from 316W to 181W. Quote Link to comment Share on other sites More sharing options...
KrazyGeoff Posted May 9, 2012 Report Share Posted May 9, 2012 :slfg: By calibrate the cheepo ones I mean to write on them +x.y where x.y is the amount I need to add or -a.b where a.b is the amount I need to subtract from the reading. Also depends what you need the temp reading for. Usually (except for that big nasty tank) I keep the temp a degree or so under the "tollerance" for the species, so the purpose to me of all the cheepo meters is for when I walk past the tanks I can glance in and as long as the reading isnt way off then I know that the heater isn't stuck full on, or off. Although I got sick of seeing 42C on the display, cause it caused dampness in my pants if you know what I mean which is why I have abandoned the digital ones, and gone for the new (old) ones that look more like a traditional thermometer, for that purpose. The fancy gadget is a "Hanna Instruments HI 98129 Waterproof pH/Conductivity/TDS Tester" which I got off amazon. The pH is at least as accurate as my blue lab device and respondes at least twice as fast, and the temp looks as accurate as my alcohol thermometer (given that the alcohol meter doesn't have a digital output). Have not done a tds comparison yet. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 9, 2012 Report Share Posted May 9, 2012 The thermostats I used on my undertank heaters was a love brand from homershams and the hysteresis coud be sdjusted. I use a digital thermometer that is accurate to 0.1 grees which also cae from there. It is portable so I use it to check any tanks, reptile enclosures or insect breeding setups. The thermostats were $340 each and three got munted in the Feb quake. Got insurance but have not replaced yet. Quote Link to comment Share on other sites More sharing options...
Rabbit Posted May 9, 2012 Report Share Posted May 9, 2012 I use a digital external thermostat by Hydor that i rigged up to my jager heater http://www.blackjungleterrariumsupply.com/Hydor-Thermostat-w-Digital-Readout_p_1224.html Quote Link to comment Share on other sites More sharing options...
David R Posted May 9, 2012 Author Report Share Posted May 9, 2012 Rabbit that looks like just the kind of thing I'm after, is it plug-and-play or does it need to be wired in? Geoff, thats what I'm trying to do with my cheapo thermometer but it seems to fluctuate by how much under it reads by half a degree or so (assuming the TDS meter is the one that is accurate and consistant). The Hanna meter looks like a cool gadget to have. Thomas, thats quite a saving! May have to look at putting some poly on the back and side of the tank that isn't viewed. That calculation does explain why the temp may be fluctuating if the heater is struggling to keep up. Alan, thanks, will look at homershams. Quote Link to comment Share on other sites More sharing options...
Rabbit Posted May 10, 2012 Report Share Posted May 10, 2012 Mine i rigged the jager up to, some have a simple plug and play. simply setting the heater to full load and tell the thermostat what you want and it will controll the heater. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 10, 2012 Report Share Posted May 10, 2012 You could wire the heater thermostat up to the new thermostat. Provided you set the thermostat on the heater to the max the other will cut the power supply as required. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted May 10, 2012 Report Share Posted May 10, 2012 On thinking a bit more: If you set the thermostat on the combo a couple of degrees higher than the stand alone it will act as a safety backup. Quote Link to comment Share on other sites More sharing options...
David R Posted May 10, 2012 Author Report Share Posted May 10, 2012 On thinking a bit more: If you set the thermostat on the combo a couple of degrees higher than the stand alone it will act as a safety backup. That would be the sensible thing to do, no use risking cooking your fish! Quote Link to comment Share on other sites More sharing options...
Faithbleed Posted May 10, 2012 Report Share Posted May 10, 2012 David, I think it may be a problem inherent in Eheim Jager heaters. I have a 300L tank + 50L sump, and run 2x 150W Jagers and they seems to do some strange things like turn on when the temps already over 27 degrees (it's set for 26) and can't seem to keep the temp at a consistent temp. Also, calibrating them is a nightmare - it took me around 2 weeks of fiddling to finally get them calibrated correctly. They seem to need to be run in a bit, because they're getting better, but for a while there I considered returning them. Quote Link to comment Share on other sites More sharing options...
David R Posted May 10, 2012 Author Report Share Posted May 10, 2012 This one has been running for about 18 months [previously on my 1400L] so should be well and truly run in. I hardly bother looking at the numbers on the dial, just turn it up or down as needed to get the temp where I want it, never even bothered trying to calibrate it. Quote Link to comment Share on other sites More sharing options...
hovmoller Posted May 10, 2012 Report Share Posted May 10, 2012 Did u see my previous post? Could be your room gets a bit too cold sometimes :dunno: Quote Link to comment Share on other sites More sharing options...
David R Posted May 10, 2012 Author Report Share Posted May 10, 2012 Yep! Thomas, thats quite a saving! May have to look at putting some poly on the back and side of the tank that isn't viewed. That calculation does explain why the temp may be fluctuating if the heater is struggling to keep up. I think you're right, it could be getting a bit cold, 300W for 400L is pushing it. Will call into Henward and pick up my spare 300W Jager to see how that changes things. Been thinking about the poly, but have a plastic background stuck on with cooling oil and don't want to bugger that up by fiddling around with the poly. Quote Link to comment Share on other sites More sharing options...
KrazyGeoff Posted May 10, 2012 Report Share Posted May 10, 2012 I just use black plastic rubbish bags taped to the 3 sides of the tank I don't look through. Seems to preserve the heat quite well? Quote Link to comment Share on other sites More sharing options...
David R Posted May 10, 2012 Author Report Share Posted May 10, 2012 Anyone used one of these before; http://www.trademe.co.nz/Browse/Listing.aspx?id=474686833&permanent=0 What about this one, all the way from Czech; http://www.top-thermostat.com/en/produkt-1564/aquarium-temperature-controller-atc-300a.html?currency=eur Quote Link to comment Share on other sites More sharing options...
FraserNZ Posted May 11, 2012 Report Share Posted May 11, 2012 Anyone used one of these before; http://www.trademe.co.nz/Browse/Listing.aspx?id=474686833&permanent=0 What about this one, all the way from Czech; http://www.top-thermostat.com/en/produkt-1564/aquarium-temperature-controller-atc-300a.html?currency=eur/quote:10voth0i That one on trademe looks like it could be the go. How does it turn the heater on/off? Doesn't look to have a socket for the power plug? Quote Link to comment Share on other sites More sharing options...
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