Bio wheels - to keep or not?

[chocochipper]

Who has an opinion on this? I've got 2 emporer 400's with the bio wheels. Should I keep the wheels on or get rid of the things?

 

[twoods71]

I believe most people will tell you to ditch them because in there opinion cause high nitrates.
I have 1 on my system and for now plan on keeping it. My nitrates are currently less then 10ppm.