| I'd say the best bet is to use half that amount and swap out completely twice as often.
I use about a half cup for 100G and change out every couple of weeks or so.
__________________ -------------------------------------------------------- Life is just a tire swing. J.Buffet
ArrecifeMadrid I keep a 100AGA SPS dominated reef. Lighting is 250W MH in a Lumenarc-III reflector and IceCap ballasts,
Tunze electronic & stream pumps, Deltec electronic return pump,
Bubble King skimmer, Deltec CaRx and ZEOvit reactor. Running since March 05 Link to my tank page on My Blog ArrecifeMadrid.com | 
