black and gray tanks drain slow

[maxx1963]

I have 3 tanks the front 2 are a black and gray right next to each other, they drain fast until about the last 1/3 and then super slow. I removed the underbelly and found they are not angled down very much and the 3" exit pipe is about 2-3 inches higher than the lowest point. I pushed on the bottom of the tank and a whole bunch more water came out.

anyone else have this issue????

[greengiant]

Mine both seem to take forever once they get down towards the end. I've never peeked to see if tanks are angled. I've seem them where the drain point is a low spot so it empty's better, but I doubt mine has that.

[therink]

I have removed the valves on my side by side front tanks due to valve problems and noticed the same thing. The tank outlets are about 1" above the tank bottom. Poor design but just the way it is. I try to make sure I flush the black tank out well between trips.