Originally Posted by jonthefishguy
Undergravel filters are more of a thing of the past. They act like septic tanks taking in all the waste underneath the gravel but a huge problem unfolds when people start believing that because the water is clear it is clean. Of the many customers that I have dealt with that use undergravel, have no idea what nitrates are or cycle. I get answers well my water is crystal clear so its perfect. I tell them, your toilet water is clear too, but I don't see you drinking that and saying its perfect
My dog seems to think its ok. This topic makes me feel real old; I can remember when UG filters were the standard, also remember trying to snake a piece of tubing thru the uplift holes to siphon out crud. On the substrate issue, IMO, CC (and flake food) are responsible for many, many nitrate problems.