Hey all I'm a little stuck on making these holes in the piping I use as a ring. It's 4mm black tubing. I have the t pipes. I just don't know how big and how many holes I should make around the ring piece of hose... Thought I might check to see if any of yous have already gone through this problem or similar. If it helps I,n just going to be trying to gravity feed these until I get my head around the concept and find a water pump. They will only be feeding four plants at the time to. Cheers