Hi! Lisa the ecaPant lady here! Glad you like the ecaPants and sorry you are having leakage! There could be a few reasons for that. Like you and hrsmom (hi!) were thinking, the older a baby gets the more they wet. A toddler’s pees can have significant more liquid than a newborn’s. Also, they can hold it in much longer so when they let it out sometimes it has a lot of force which and is harder for a diaper to absorb quickly. The best solution in these cases for ecaPants is to add an insert in the tunnel pocket. You can buy inserts made for ecaPants, or even just fold a wipe or washcloth up and slide it in the pocket. The inserts add a lot more holding power. When I add 2 in mine I can usually even use that at night with my toddler. Babies are all different so some may never need the inserts, but others do.
Other things that can affect absorbency are fabric softeners. They leave a repelling coating on the diaper fabrics that can cause leaks. Also pure soap detergents can do that, as well as some diaper lotions, etc. The best thing to use is a natural detergent with no fabric softeners or bleach. Bleach can eat up the waterproofing ability. If you have used fabric softners or other things that cause repelling, you can try stripping the ecaPants to wash out the build up. There are different methods online you cold try. Zany-zebra has many:
http://www.zany-zebra.com/stripping-cloth-diapers.shtml
If you have any more questions, please feel free to PM or email me anytime!