it'll be better if u switch off all the PHs and filtration system...
i think u're reffering to LIVE baby brine and not frozen ya? if that's the case, then u just put a little in your tank... overfeeding is not really good..
err actually underfeeding ain't good either..
actually, if u put alot of it in, leave the pumps all switched off for abt 15mins.. then switch them all on, the remaining of the shrimps might get sucked into your filtration system...