Strange Creaking Sounds..........how Scared Should I Be?

I would have thought it have gone by now if it was going to.  The creaking may just be due to expansion and contraction due to temperature changes or to slight shifts in the floor if you have a suspended floor.  You seem to suspect that it is due to temperature changes; how long has it been happening more often?  If it's just the last few days, it may be due to the cold spell we are having.

Be afraid.... be very afraid..... http://www.bbc.co.uk/news/world-asia-china-20850048

 

If your tank is making a clicking noise and you've ruled out your mechanical equipment, fish, plants and decor, then it could be the tank, or the absence of a drip loop in a cable going to your electrical wall sockets. Condensation can form on electrical cables near your tank and without a drip loop can travel down the cable and enter the plug creating a clicking noise by electrical arcing. A drip loop is simply created by making sure the cable hangs below the wall socket before going back up into the plug. Just a few inches will do the job.

As for the tank, the weakest and possibly noise causing component is the silicone seal, as it will deteriorate over time. Depending on its quality and application, a lifespan between ten and twenty years is probably a reasonable estimate. The glass and metal frame, if looked after and free of flaws, will last eons longer and shouldn't really make any audible noise.

With regard to temperature changes causing a tank failure, the following should put your mind to rest.

A 1 meter length (any X-section) of aluminium will increase in length by about 2.3 mm after a temperature increase of 100 deg C. A similar length of ordinary glass will increase in length by about 0.9 mm and steel by about 1.4 mm, after the same temperature increase. Very high or very low temperatures do not follow the same principle.

The temperates inside your house, or tank water are not going to change by anywhere near 100 deg C. (If they do, consider moving fast.) So, the actual changes in material lengths are going to be very, very tiny and the flexible silicone layer, between 2.5 and 5 mm thick in normal residential aquariums, squashed between the metal frame and the glass will easily absorb any changes, but could make a clicking sound as a result. With a good silicone seal it is highly unlikely that your tank would break as a result of your normal house, or water temperature changes.

If the silicone is going to fail, it would probably be due to age deterioration rather than any temperature changes.

After all that, if the tank is older than ten years and the clicking has accelerated recently I would seriously consider changing it for a younger model.