If you are dosing a variety of additives such as calcium, alkalinity, magnesium, trace elements, and maybe a nutrient supplement, it can quickly turn into a confusing mess of dosing lines, and it's important to keep different additives separate to avoid cross-contamination. With a total of eight color variations between the two sets, you'll have no trouble telling your additive lines apart. Each set includes 10 feet of each of four colors, giving you a good amount to cover typical dosing setup configurations, and the air-resistant TPE tubing has been selected for a long service life when dosing common reef additives.