i bought one from polyart last week.
it has been running in my 2x1.5x1.5 tank for the past week.
initially i had an aro in there, ammonia level was 2.0
i transferred the aro to my FGT, so tank was fishless and i left the filter running.
tested it today, 4 days later.
ammonia level still 2.0
same colour on the colour chart.