jason the filter freak January 30, 2014 Share January 30, 2014 I have a 30 Gallon AIO tank. I've long been of the mind set of getting a slightly undersized heater so if it fails in the on position it doesn't cook the tank. Is this the right mind set.I've been partial to the eheim heaters for a while. wondering if thats what to stick with or if there is something more reliable on the market?I've heard about a neo therm? Link to comment Share on other sites More sharing options...
nova423 January 30, 2014 Share January 30, 2014 Eh, depends on how warm you keep your house. If you keep it at 65, your undersized heater would probably be struggling keeping things in the tank warm. Best bet, TWO undersized heaters with one set below your target temp. Link to comment Share on other sites More sharing options...
Origami January 30, 2014 Share January 30, 2014 I don't know neo therm, so I can't comment on those. That's an interesting take you have on undersizing a heater. Unfortunately, it leaves you with a single point of failure. If the heater fails in the off position, there's no backup. If it fails on, then the max temperature that the tank will reach is set by a complex relationship between the ambient temperature and how fast the tank can give up the heat. In the summer, your home is probably warmer than in the winter. Therefore, if a heater fails on, it will reach a higher temperature and that may be, in itself, damaging. A better approach might be to use a higher reliability controller (something like a Ranco) rather than relying on the cheap, failure-prone bimetallic strips in most heaters. Or use an aquarium controller with either redundant temperature probes or logic designed to identify a failed temperature probe. Eheims definitely have a good reputation. I ran the old style Stealth heaters for years but pulled them after the second generation of heaters (they had a light in the cap) were pulled off of the market. I replaced them all with three large Eheims managed by my controller. I have them set to come on one at a time. If one can't bring the temperature back into range, the second kicks in. And if two don't do the job, the third kicks in. Link to comment Share on other sites More sharing options...
ArtC January 30, 2014 Share January 30, 2014 I remember Sanjay giving a talk on backup systems at MACNA (Orlando?). He's an engineer and gave a system engineering failure analysis. Basically said that the more parts you put in your tank the more things that can go wrong. Your backup system gets exercised (tested) very little, so it tends to be the least reliable component. He was using his own backup design as an example. My suggestion is to keep the human in the loop. Set up your controller, but instead of giving it control over emergencies have it contact you when it detects a problem so you can deal with it correctly. Don't automate the backup heater unless the primary failure will result in sudden death (and the two heaters together can't cook the tank.) Link to comment Share on other sites More sharing options...
Origami January 30, 2014 Share January 30, 2014 I remember Sanjay giving a talk on backup systems at MACNA (Orlando?). He's an engineer and gave a system engineering failure analysis. Basically said that the more parts you put in your tank the more things that can go wrong. Your backup system gets exercised (tested) very little, so it tends to be the least reliable component. He was using his own backup design as an example. My suggestion is to keep the human in the loop. Set up your controller, but instead of giving it control over emergencies have it contact you when it detects a problem so you can deal with it correctly. Don't automate the backup heater unless the primary failure will result in sudden death (and the two heaters together can't cook the tank.) That's a simple, serial (chained components) analysis that pre-supposes a mode of failure. A parallel combination of high-failure rate components is a frequent means of increasing the overall reliability of a system through redundancy. Link to comment Share on other sites More sharing options...
Origami January 30, 2014 Share January 30, 2014 Let me elaborate. Let's assume that a particular heater has a mean time between failure of 1,000 operating hours (we give this a failure rate, lambda, of 0.001). Let's further assume that you have an external, high reliability controller available to you that has an MTBF of 10,000 operating hours (lambda = .00001). These are hypothetical numbers used for demonstrating the reliability analysis. Let's consider three cases. A single heater. A single heater in line with a single controller. Two parallel heaters in line with a single controller. Case 1: Single Heater Failure rate is .001. MTBF is 1000 hours. This is your base configuration. Case 2: Single heater serially connected to a high reliability thermostat. Failure rate is (.001 + .0001). MTBF is 909 hours. This is what Sanjay was talking about. The mean time between failure is worse than the base configuration. The more components in a serial stream, the higher the failure rate. Case 3: Redundant heaters connected in parallel controlled by a high reliability thermostat. Failure rate is (.001 || .001 + .0001 = .000101). MTBF is 9900 hours. This is what I am talking about above. In this case, the redundancy of a high failure rate component makes a huge difference in the reliability of the overall subsystem. This same parallel redundancy approach is applied everywhere, whether it's in data encoding for reliable data transmission, in RAID hard drive configurations, spacecraft design (where I've got experience), etc. To implement this in Jason's case, it is appropriate to select multiple, undersized components that, taken together, provide adequate heating and to pair it with a higher reliability controller. In that design scenario, a single heater that fails on is unable, on its own to cause system failure and a heater that fails off is backed up by redundant heaters. The end result is a higher reliability subsystem design. Link to comment Share on other sites More sharing options...
AlanM January 30, 2014 Share January 30, 2014 Good read. Thanks for the nice explanation. Link to comment Share on other sites More sharing options...
dbartco January 30, 2014 Share January 30, 2014 Like the new Cobalts personally Link to comment Share on other sites More sharing options...
dbartco January 30, 2014 Share January 30, 2014 Oh, and Sanjay had a huge tank crash while at this MACNA in FL. Link to comment Share on other sites More sharing options...
nova423 January 30, 2014 Share January 30, 2014 I made a controller with a home depot trip and this temperature controller. Note it is the just the heat controller and not the dual channel. Perfect for running two heaters and all together cost $25. I keep one of my heaters plugged in the wall GFCI and the other goes into the heat controller outlet. Link to comment Share on other sites More sharing options...
jason the filter freak January 30, 2014 Author Share January 30, 2014 Hmmm yea the tank is in the basement which typically stays sub 76 year round. Its got a sicce pump, vortech power head, and LED lighting so ambient heat soak is not a strong issue such as the days of danner mag drive pumps, maxi jets, and metal halide lighting.I don't want want to run a controller on the tank, I actually just sold my never used reef angel. I think two heaters that are under sized as the chances of both failing at the same time is minuscule and failing in the on or off position with redundancy shouldn't result in a harsh enough environmental swing to crash a non SPS/LPS tank. \ P.S. Tom thanks for an incredibly interesting and well detailed reply, this is why I keep coming back to wamas. Link to comment Share on other sites More sharing options...
brad908 January 30, 2014 Share January 30, 2014 This is why you buy an Apex. $200 Apex Jr, can save $1000's in livestock. Link to comment Share on other sites More sharing options...
hawkfish01 January 30, 2014 Share January 30, 2014 I have 2 cobalt neo therms and i love them, 1yr+ and no troubles at all...8) Link to comment Share on other sites More sharing options...
jason the filter freak January 31, 2014 Author Share January 31, 2014 This is why you buy an Apex. $200 Apex Jr, can save $1000's in livestock. Its a 30 gallon tank, with non SPS/LPS, my live stock list is unlikely to exceed $150. The pump has a built in controller, the light has a built in controller, regular water changes with a carefully balanced tank should be stable enough. Link to comment Share on other sites More sharing options...
Orion January 31, 2014 Share January 31, 2014 This is why you buy an Apex. $200 Apex Jr, can save $1000's in livestock. It can.... IF someone is home to deal with the situation Link to comment Share on other sites More sharing options...
worm5406 January 31, 2014 Share January 31, 2014 (edited) It can.... IF someone is home to deal with the situation Yeah or the heater does not fail. Like the new Cobalts personally I have had a bad experience with these new cobalts. They (Cobalt) have contacted me and I have sent all of mine back for them to investigate. Basically it was throwing electricity into the tank. I am waiting on them to respond with the resolution. Right now, there re NO cobalts in the production tank. QT -- yes, but NOT production. Edited January 31, 2014 by worm5406 Link to comment Share on other sites More sharing options...
zygote2k January 31, 2014 Share January 31, 2014 Ebos are probably the best on the market, why scrimp on quality? Cobalts are just rebranded cheap heaters, Stealths all bubbled and either caught fire or shocked people, WON brothers and Coralife had similar issues, Visitherms last for a few months before moisture builds up inside. We've tried nearly every heater ever manufactured and Ebo Jager is the hands down winner in terms of reliability. Link to comment Share on other sites More sharing options...
AlanM January 31, 2014 Share January 31, 2014 Ebos are probably the best on the market, why scrimp on quality? Cobalts are just rebranded cheap heaters, Stealths all bubbled and either caught fire or shocked people, WON brothers and Coralife had similar issues, Visitherms last for a few months before moisture builds up inside. We've tried nearly every heater ever manufactured and Ebo Jager is the hands down winner in terms of reliability. I just wish they werent so long. Link to comment Share on other sites More sharing options...
AlanM January 31, 2014 Share January 31, 2014 By the way, the last heater thread here established that finnex ones were trouble. Chalk up one more on the trouble pile. I have a 200W one on my saltwater mixing can which cant get the temp from 60 to 78 in three days of trying. It peaked at 71 and only gets warm to the touch. Link to comment Share on other sites More sharing options...
worm5406 January 31, 2014 Share January 31, 2014 What size Finnex? Link to comment Share on other sites More sharing options...
Matt LeBaron January 31, 2014 Share January 31, 2014 I've had bad experiences with Jagers, out of the three I've owned two have malfunctioned. One died outright and cost me a couple months or coral growth before I caught it (this prompted my purchase of a Reef Angel Unit) and another stopped reading temperature correctly. I kept using the second one for a while because I was controlling them with the Reef Angel by then but without that it would have tried to slowly cook my tank. Third one that I use in my mixing container and it is still working fine but I don't care so much what that one does. Having said that though the only type of heater that I have had over the years that didn't fail, malfunction, or start tossing current into the tank after a year or two were the Rena Stealth heaters. I used some of those for YEARS without any problems and I still have one that I use with my QT tank that is easily 5 years old at this point as it first saw duty in my freshwater tanks back then. Now granted it hasn't seen constant use over that time but it did get 2 years of solid use and then another 3 of occasional use in my QT. Unfortunately they stopped making those heaters. At this point I just replace my heaters every year. I use two for my setup so it costs me about $100 or so each year but with the number of SPS I have and the growth of all of them at this point it's a no brainer for me. So long story short, I'd recommend a controller and save yourself the heart ache. Link to comment Share on other sites More sharing options...
hawkfish01 January 31, 2014 Share January 31, 2014 Had an ebo...wouldnt hold temp to save its ***...so i went with cobalt.. Link to comment Share on other sites More sharing options...
jason the filter freak February 7, 2014 Author Share February 7, 2014 Well this escalated quickly. I still think I'm going to go controller less with two undersized heaters Link to comment Share on other sites More sharing options...
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