anyone use de nitre nitrate removeal from seachem before?.
 

i started using this stuff about a month ago and i have 0 nitrates now, was wondering if i need to replace it or is there any ill affects of just leaving it in my reactor?

Once saturated it may leach back into the system. I would replace like everything else

I think the working principles of seachem denitrate are anaerobic and/or aerobic, i.e. bacteria is behind both of these processes. There shouldn't be any harm to leave it attached to your tank.