My 2.5 year old had tubes at 10 mths. I clean his ears daily because the wax is dark brown. Is this normal? And how long do tubes stay in?

See below. The wax is not secondary to the tubes. Ear wax provides a protective benefit to the ear canal. It can help prevent infections. Some kids do tend to make more wax than others. Clean what you can see with a safety q-tip.
Don't Clean. We do not recommend cleaning out ears with q-tips, as you're more likely to just push the wax back and cause an impaction that could lead to hearing loss and ear pain. Tympanostomy tubes usually stay in until they fall out on their own after one year or so, but if you are concerned, follow up with your pediatrician or an otolaryngologist. Don't worry about the color of the wax, no need to clean.