AQUANEAT Aquarium Thermometer, Fish Tank Thermometer, Digital Temperature Test, with Large LCD Display (1 Pack)

The six pack is incredibly cheap. Comparisons to other less-fragile designs are unhelpful because the cost will always be much higher than this very common design. This specific design is sold under many different names/brands, but clearly, it is the same product (if not from the same production site, it is at least identical tooling/materials/process). ALL brands of this design have a set of known design flaws. The juncture of the cord entry to the case is susceptible to disruption; the tension of the battery spring/contact is subject to fatigue; and the force required to remove/replace the battery compartment cover contributes to a shorter life of the instrument, which may, or may not, be related to the aforementioned battery contact. All of these details indicate that the set of best practices is to install the unit with care for these design limitations: avoid de/reinstallation cycles; avoid removal of the battery cover; avoid variable tension to the wire at the junction to the case; install the control box at an angle conducive to ease-of-viewing (so that there is no need to manipulate the control box to see the readout. All of this contributes to approximating a single installation event with no further touching, tilting, pulling, or pushing. [Consider my description as an unreasonable goal, but I hope that my description will at least set an expectation the product’s durability is inversely proportional to the user’s divergence from the goal.] Most of the criticisms of this product are based on inappropriate expectations for its design, including the unfounded assumption that its design should allow for relocation and transfer to a series of installations over time. My solution to that problem is to use a different, more robust (and more expensive) instument. Nothing about the product’s marketing suggests that it should be anything but a single, permanent installation. That said, I have successfully dis-integrated and re-integrated these from time to time, with success, but ALSO with care and forethought regarding the fragile points of its design. Reports persist that certain brands of this singular design are better performers than other brands, and it is clear that these reports are speculative and that the reliability factor between brands is within the bounds of the statistical likelihood of failure across ALL brands. I have used approximately 75 of these units over a period of 5 years, of 5 different brands, and my experience is unexceptionally consistent: some units fail more quickly than others, irrespective of brand/source; the risk of failure correlates with the number of times the product is moved or its placement reconfigured. The risk of failure caused by removal of the battery cover is substantially higher than other sorts of manipulation (for example, dropping the box, or tension on the cord). The reason for this is that the removal and replacement of the cover, while a simple task, requires substantial pressure on other parts of the box to provide the leverage for the maneuver, and these random, repeated squeezes of the outer case seem to be associated with deterioration of performance (such a the display). The suction cup threaded to the wire is most likely present to achieve a specific task: to maintain appropriate constant tension (or lack thereof) to the cord with respect to the junction at the case. Whether applied tension is the designer’s intended method of installation is not certain. However, use of the suction cup to preserve a steady-state of the cord tension seems to be a successful aspect of installation. The junction of the cord to the probe-head seems uniformly robust and has never been a point of failure in my experience. The fact that the unit comes with an extra battery should not be construed as evidence that the unit is designed to last longer than the life of the first battery. Rather, I consider the extra battery as a bonus in that I hold these in reserve for other applications (it is a commonly used size/voltage in small electronics)…the retail price of the extra batteries alone exceeds the actual cost of this 6 pack of units.