OK, so what your saying is I should use max cap in my dual di's that are on the ro unit itself and use silica buster in my add on dual final stage di ?? I will most likely get 6 months out of my present di so it will be intresting to see if I get more time out of this brand.I am just now seeing 1 tds out of the unit and still getting 0 tds from the final.The dual carbon block water buster's I run do a fantastic job.So I will most likely just change at the six month point to do the testing.I need to look at the other di document you linked along.I already have two dual inline tds meters installed so keeping track will be easy enough.Both these meters have been checked with a hand unit also so accuracy should be fair.We presently use aprox 60 gallons of ro a week with TO and weekly water changes.So that's over 900 gallons of good water in six months. I'm going to check out the super DI and decied how I am going to do this.I will update as I go.Anyone with experience with this new di your input is more then welcome and thanks for the input already given. Keep it comeing