It might also work to use a smaller hot nail to melt a hole. Once the system is running, check for leaks around the poly tube and barbed tees. If any drips appear, pull on the tees to reseat them and stop the leak. Use cable ties to hold supply and drain lines together. The system should be run for several days on plain water to find any leaks.
Any system can leak so if it is placed indoors be prepared to mop up water.
Keep the return pump on or below the ground. If it rises up at all, the level in the return pipe will rise above the holes and flooding will occur. If it is possible to lower the return pump below ground level, use the elbow assembly. Do not allow roots to obstruct or grow into drain holes or the system will overflow. This is a real problem with agressive plants like tomatos and cucumbers.