After a lots of reading in this forum, I'm looking at isolating my KDF into another tank.

I currently have a Greenway (Sanitizer) system which has CR-100 zeolite and KDF-85
in a 10x54 tank with a Clack valve.

In the beginning I only had the CR-100 to remove hardness and Iron and worked great
for 6 months, than some H2S appeared.

I Was instructed to add some KDF (on top/wrong) which took care of the problem
for another 6 months, but some trace of H2S came back.
As my media was pretty much new I decided to mix it up to extend the life of that set of media and bring the KDF to the bottom and CR100
on top and see if the problem would be solved. According to the company the KDF should get a proper backwash this way.
I only wish those tank were transparent to confirm

I'm now back to the original problem which is .....If I open a tap, the water has NO smell for 40 ounces than I get a smell for the next 40 ounces
and than OK for as long as I draw water. And this scenario repeats itself very constantly.

The company send me a new set of media to re-bed it properly, so I have that set of media on standby.

A few question to start....

Does the KDF need to be brined with the chlorinated water or just backwashed with water????

I'm thinking of a second tank 10x18 (KDF) so that it doesn't get hard as a brick if not backwash properly...