[leebca]

Brine shrimp are the 'garbage eaters' of the salty waters. That is, they are non-selective filter feeders willing to consume any biological particulate matter.

They can be gut loaded with anything of the appropriate size (about 20 microns). Spirulina and HUFA are the most common. There is nothing wrong with loading them with phytoplankton. (Phytoplankton is one of their 'natural' foods). Selcon is a great source of HUFA.

The gut loading depends upon the density of the 'food' in the water. There is an optimal density. Too much and it is wasteful, too little and the brine shrimp don't 'run into it' often enough. Other parameters are having enough feed but no excess which pollutes the water and harms the culture, or which produces too much bacterial activity (which they will eat along with or instead of the gut loading food). Only food that is suspended is eaten by the brine shrimp, so their feeding depends upon the food being in suspension (usually using an aerator) BUT not so strong as to hinder them taking in the food.

If it sounds complicated, it is. There is no definitive answer to your time question because of all these parameters. Most people learn by experience. The best way to tell if they have been sufficiently gut loaded, without going through the 'math' is to take some out and look at them. If their gut looks bloated, they are 'stuffed.' If you're new to what you're looking at, simply separate some out and don't feed them, so you have something to compare them against.