Does your reactors come with the carbon post filter or is it a add on etc... I saw pix from your early designing fazes and it showed 2 reactors but your final result has a single with paper media inside... Is there a carbon chamber inside or do I build that myself haha.... Looking to buy one after I find that out... I hooked a ozone unit to my skimmer and I hate it not getting the skim mate I used to...