ok I love my penguin filters. have had them since I started my first 10 gallon tank about 3 years ago. only thing is I also love sand. I have it in my 55 and also had it in my 10 gallon. now the sand destroyed my filter in my 10 gallon so I switched over to gravel and now have gravel in my new 20 gallon because of that problem. now my question is this: is there any way I can possibly keep the sand out of my filters in my 55 gallon. I have had no issues with my impelers in my 350's but I hear the sand grinding in them every now and then. so any ideas?