If the pH is less than 6.5 or higher than 7.5, you will leach copper or iron (though iron leaching decreases sharply as pH rises) from pipes, and copper, zinc and lead from brass and bronze fittings, and of course, older solder. You can pickle the brass to remove most of the lead and lose copper and zinc on the surface, but over the years (15-20 in drinking water with neutral pH), the next layer of copper and zinc (brass) will also dissolve away exposing new lead. In typical low pH hydroponics solutions, leaching will be much faster than drinking water.

While plants need copper and iron, high concentrations will stunt growth of both root and vegetation. Plants are less sensitive to iron than copper and iron leaching generally requires a pH below 5, but it will leach above 5 too and become toxic. The leaching also occurs mostly in standing water, so running the water for a while will flush out the "extract" portion that's been sitting in contact with the metal. That works for drinking water or hydro drain to waste, but in a recirculated system, it all becomes extract will continue to build up.

Thank you for your detailed answer Zathras! I need something strong and rigid for this application. Do you think using a galvanized metal would more beneficial?

Again Thanks,
Flawless

Just use a food grade high-density polyethylene material - cheaper than using galvanized metals, less leaching risks.

Galvanizing is just plating zinc on steel and oxidizing it. The nutrient solution will strip that off and attack the remaining zinc and steel layers. Galvanizing protects against rust, but not low pH solutions. There's also lead in galvanized pipes. Galvanized steel lasts a little longer than bare steel in drinking water pipes, but still corrodes over time.

I would suggest PVC,ABS or HDPE. They can present their own problems, but are safer than using metals for pipes and reservoirs. I suppose you could always run PVC inside metal if you need both strength and safety.