i got a bottle of DT's phytoplankton from LFS this weekend, and it rrecomended 1 oz for every 100 gal, and i have a 125 gal, so i added about 1/3 of the 4 oz bottle , and it said do this daily, well at $8 a bottle it would be about $2 a day which seems expensive to me, on top of the brine shrimp...