Why is my irrigation stuck?

[Roodvlees]

Above this picture is a Metal Refinery which cannot work anymore because the output pipe is blocked. I recently changed the supply pipe from a normal Liquid Pipe to an Insulated Liquid Pipe. In order to avoid heat dissipating in the base instead of on the my Pincha Pepper plants. However, as can be seen in the image, there's still liquid flow from this insulation to the existing pipes. When I initially built this setup there was even more flow than the plants could use. The excess flow could just continue and be dumped in my polluted water storage. As you can see the pipes for the 4th and 5th plants are connected.

However, for some reason there's no flow from the 4th to the 5th plant. Causing only the 1-4th plants to maintain growth and preventing the 5-7th plants from growing. Those last three plants have all conditions met except irrigation.

What could have caused this to change?

[meekay]

Pipes only flow one way, and networks will only work well if they are either:

* one source branching to many sinks, OR

* many sources converging to one sink

This screenshot doesn't show the whole network, but it looks like you've got:

source (offscreen above) -> sink x7 (the hydroponics)  <- source (the bridge) <- some other source offscreen upper right?

Hydroponics act as sinks. Depending on the order in which things were constructed that's going to cause confusion like what you're experiencing. Sounds like between #4 and #5 a pipe has decided it will only flow left, and that's why those plants are starving. 

The best way to resolve this is to have the hydroponics on a spur that's only fed from one end. For complex networks you can force flow in a particular direction using bridges, as long as the pipes between each bridge are either one->many or many->one.

[nakomaru]

Basically what you have:

Simplified:

You have two outputs facing towards inputs. Fix it like this:

[AznDumbum]

Here is my take on the solution on your existing design. You have a bridge that is splitting it's output to bottom and top.
I am assuming you want the polluted water to flow from left to right.

If there are any entry into a pipe (Green), it will always force a flow towards towards an exit (White) of the pipe that exists as a direct path it has access to,

To fix, you would need to force to break the pipe from Green to White on the RHS and place a bridge there there instead.

Would look like this:

 

[Roodvlees]

Thanks guys, that fixes it  liquids are flowing at full speed again.