My tank is designed to be low WC because I feel this will, theoretically, tend to be more stable. The success of this depends on what accumulates. Until now I did not know what happened to DOC in this kind of tank... Here's Barr's answer to that question:
"... we export DOC's with water changes, non CO2 tanks on the other hand w/no water changes do not have that export, so then the bacteria start to break it down into CO2 and energy via respiration which removes??
O2 to oxidize the DOC(reduced carbon).
Th low bioloading in non CO2 tanks is mainly to match the low NH4 removal and limited supply of CO2.
Many folks have more fish and more algae, but it's less to do with the DOC;s, but to some degeree that can reduce the dOC loading by having less fish, but plants are also a large source of DOC themselves, like 10% of their fixed carbon is leached out as DOC's..........
So... I won't add activated carbon or purigen... It turns to CO2!!! HA HA HA HA! (you win some
I may still have to consider using zeolite though... The jury is still out on what my plants can do with my bio load, though. And more plants may come. Emergent plants should take it up a notch or two.