No problem! Good luck on the tank and filter, hope I was of some help to you :)
And just fyi, there are some folks that I know who have had the same batch of Matrix or Substrat Pro in their filters for the past five years. The stuff lasts forever - all you need to do is give it a rinse in tank water every now and then to prevent any possible clogging. No replacing necessary. The only problem that I've had with my version of your filter is that the silicone tubes get really dirty after a while, but there's a flexible bottle brush contraption that they sell at PetCo that cleans them.