seachem prime ex???? it cost only abt $10 from petmart. very cost effective too. 1 capful (5ml) supposingly treats 200L of water...... even claims to reduce ammonia & nitrite. not 2 mention reduce chlorine and chloramine too.
pls check out the lfs info centre. address and info r all there. anyway, this is the link to sealife.
http://www.sgreefclub.com/forum/index.php?showtopic=14085