Undergravel Heater

[daleboy]

I hate to see heaters in the tank so was looking round for alternatives and stumbled across undergravel heaters.
Has any one used one?
Are they any good and if so can they be used under sand.

Thanks in advance
Dale

 

[tonyp5467]

i use x2 3ft heat mats under my 6ft x 2ft x2.5ft tank and have had no issues at all even in the cold weather we recently had
ive not used them with sand but i use them with 2-3mm black quartz gravel with no issues so i cant see sand being a problem