personnaly i do not think that is an excuse, i have used mine for 2 years next week
i use 20k XM's and i highly recommened them, I know i am not the only one who has used them that long and still has had good results.... check out carl swaby's (i think i spelt ur last name wrong carl) tank tour video on,
www.reefvideos.com it is the 2nd last video in the chart
he has a gorgoues tank (p.s. he is the owner of fragfactory)
HTH,
Zack