the school serves roughly 2000 students, mostly from south, west, and central fort collins. thus, if the mood at the time of recall does not match the mood experienced at the time the event occurred, there is an increased chance that complete recall will be affected/interrupted. it requires a special playing technique known as "circular breathing," which is tricky but produces a continuous tone, without pausing to take a breath. the handling is much more convenient in the case of pet bottles. for this reason, there are melting tanks that are specially coated for candle wax melting. 