Thank you. I ironically adjusted my durso drains yesterday morning hoping to turn over more water to fix this. And did so successfully despite how much of a pain dursos are! One feeds into my RS mat and I just ordered some filter socks for the other drain. Hope this worksNo. That is usually a mechanical filtration issue and can be dealt with via finer filter floss, filter roller, or polishing filter like the Marineland Magnum after a water change/deep tank clean. Also check the water level in your sump. If it is too high your water may not be getting process appropriately in the sump (World Wide Coral posted a great video on this subject today).

