a huge hang-on aquacmora 'nano' skimmer, 18 inch tall (same heighta as my tank >_>) im not using those ceramic rings or carbon bag, but i just put the sponge back in to filter out some dusts, and i clean it in RO water once/week
how frequent should i do water change? 1 gal/day for a 12gal? (kinda change salt from oceanic to something called 'marinemix professional', my LFS told me oceanic sux due to the low pH thing) and i got 0 nitrate, just want to know what to do incase i got a spike or something.
p.s. currently im change 1-2 gal every 3-4 days with new salt.