'Lo All, The Celestial came with sight gauges made of clear nylon reinforced vinyl hose installed on hose barbs with clamps. There is a valve at the top and bottom of the lines running from the bottom of each tank to the top of the tank. Over time, the vinyl does stain from the dye in the fuel. But - the price of the hose makes it an easy maintenance item. Leave a small bend in the line so if it shrinks, it will not tear or pull off the hose barbs. To change hoses, if the tanks are full close, the top valve; otherwise, leave the bottom valve closed, remove the hose from the top hose barb. Using compressed air (or just blow) into the hose, open the bottom valve until all fuel is forced out of the hose, and close the valve. Don't let the open end of the hose drop below the level of the fuel in the tank when the valve is open! Check to see that the bottom valve is fully sealed and no fuel is reentering the hose. Place an absorbent pad under the hose/barb. If all is OK, remove the hose from the hose barb. Oh, be careful not to turn the valve or hose barb on its threads, as a leak could result. A sharp knife is best to help remove the hose by cutting the hose lengthwise along the barb, as no stress is then placed on the valve or hose barb. Install the new hose, making sure will have a small bend in it when fully seated on both hose barbs. Clamp securely. A good safety precaution is to turn off the bottom valves just in case something should happen. On the day tank, which is the lowest tank, I turn off both top and bottom valves as it is possible a leaky valve could syphon fuel into the day tank. YMMV, cheap advice/information is worth what you pay for it -- so CAVEAT EMPTOR. Take care and be safe. Wayne M/V Celestial Albin 43 Sundeck