Hi there, I'm new to hydroponics and I'm trying to get an NFT system up and running. I'm having an issue, though. As you can see I have two pipes, with irrigation line feeding water into them. They're hooked up to a 500gph pump in a 30 gallon nutrient basin. The issue is, water will flow into one pipe continuously at a good flow rate, but inconsistently in the second. I've tried several setups - this is the most recent. All have the same problem.

After reading some posts on here, I'm wondering if I need to instal a line that sends overflow back into the basin? Any help would be much appreciated. Thanks in advance!