Maximimizing the BBS Hatch

Hatching brine shrimp eggs can be frustrating. You have to get all the hatching conditions just right or the hatch will completely or partially fail. The aim of this short article is to show you how to get the maximum hatch from your eggs.

Vendors tend to sell BBS (artemia) eggs at different prices according to the hatch rate, e.g. 80% or 90%. I use 90% hatch rate because unhatched eggs tend to get into the tanks, clogging filters. The 90% eggs I use should only show a few unhatched eggs if I get all the parameters correct.

Container

As you can see in the photo, I use a simple water bottle with a basic V shape to it. The V shape improves the efficiency of aeration and allows the live shrimp to settle into a contained area for harvest by siphoning. The container is about 1 liter in size. I do not fill the container up to the top.

The advantage of a container like this is that it is easy to clean. I have three different containers which I rotate and then clean at least once a week. I take them to the sink and use a long handled brush with soapy water to remove the scum that builds up on the inside of the container. Since I started adding bleach to my hatchery I have found I don't have to clean the containers any more often than this.

Light

You can see a fluorescent (rated at 60W) light shining on the hatch 24 hours a day. There is a bit of plastic between the light and the bottle to prevent water from splashing on the bulb.

Storage and Use of the Eggs

I try to keep the eggs as dry and cold as possible. Moisture can quickly reduce the hatch rate of the eggs. I store tins in my fish room fridge. When I open a can, I transfer the contents to a plastic bag, wrap it up tight, then put it in another freezer bag and store it in the freezer. I only take out as much as I will use in 3-4 days. Even these are stored in resealable plastic bags.

For the amount of water you see in the container above, I use two and a half "scoops" of eggs (see the small scoop in the picture below). This is enough to feed a fifty tank fishroom. Newborn fry are fed three times a day. After three days they get two feedings of BBS and one feeding of finely crushed fish food a day. After three weeks or a month all guppies get only a morning feeding of BBS.

Salt

The amount of salt to add to the hatchery is critical. I have noticed that huge swings in the hatch rate are associated with the amount of salt I use. For the hatchery you see above, I use a tablespoon as a measuring device, but I do not fill it up level. What I suggest is that you adjust the amount of salt according to the brand of BBS you have purchased. Set up three containers and give them each a different amount of salt. The next day the hatch rate should tell you how much salt to use, or you may have to go another round. This is the parameter that seems to be the most critical.

pH

I have found a simple way of ensuring that the alkalinity of the hatch mix is correct. I use water from a container that has coral sand in it. The coral automatically adjusts the water to the correct pH for hatching BBS.

Temperature

My fish room is set at about 77⁰ F or 25^o C. The light probably gives off a negligible amount of heat.

Sterilization

When I first set up a hatch, I add four drops of bleach to the water. This is recommended to kill harmful pathogens that might be resident on the eggs. This also helps keep the hatch from spoiling and means you do not have to clean the containers as often.

Aeration

Finding the right amount of aeration to keep the eggs in suspension is difficult. Too much aeration and the eggs are washed up on the sides of the hatching container. The end of the air line tends to collect salt. I have found whacking the end of the air line on the rack usually dislodges it.

Hatching and Storing the Hatch

The hatching time of eggs can vary from one source to the next, but I have found setting up a new hatch every twenty-four hours usually works. After the eggs are harvested, I store the left over BBS in the fish room fridge. This slows down the metabolism of the BBS, preventing them from consuming too much of the nutrition they contain.