Question: Brine shrimp hatchery not as productive with each new attempt.

[piaalexa]

Hi guys,

So I was following the hatchery tutorial (which is great by the way) and for the first two times I got a really good yield of BBS. However the last couple of times I have followed the procedure I have been getting less and less shrimp hatching. I am really confused what I am doing wrong because I did identical to the first two times. I am lucky that I am only looking after 6 babies but I am concerned that eventually none will hatch if it keeps going like this. I am running two at the same time, and this time I have tried adding a little more salt to the one just to see if this helps.

I am using aquarium rock salt which is mostly in coarse sand to gravel sized grains so I have been adding half a teaspoon, or at least until its a little salty like a potato chip as the tutorial mentions. Like I said up until now I did not change anything and yet I am losing productivity in my hatchery. I am even using two lamps to help keep it warm. I would appreciate any feedback on what else I could try

 

[auntiejude]

I use a water bath to keep the temp steady - just stand the hatchery in a small tank with a little tropical tank heater to keep it at 25C. Sometimes just leaving them a little longer affects the yield.

If your ambient temp dropping? Your hatcheries could be cooler now than before if your weather is changing.

How old are your BS eggs? I know they are supposed to last for years, but if they get too hot or damp I guess they could be affected.

 

[piaalexa]

Hi auntiejude,

I have had the eggs for 9 months and kept them in the fridge. It did cross my mind that they might be old but the first hatchery showed that they were fine as I got a lot hatching.

Yes temperature may just be slowing the hatch rate. It's winter here and this last week got really cold. Maybe putting the hatchery in a warm bath might help, thanks :happy:

 

[bugdozer]

Do you live anywhere near the coast? I tried using real seawater as an experiment and it gave me a much better hatch rate than I ever got with adding salt artificially. Although not very practical if you live inland!

 

[piaalexa]

I don't at the moment, but I can imagine seawater would help a lot!

I decided to add quite a bit more salt than my previous attempts and have been getting a significantly better hatch rate - feel so relieved to see my little ones with big orange bellies again - hooray!

I guess what confused me was on the tutorial thread many people were concerned about adding too much salt (especially with the rock salt which is what I am using).

 

[bugdozer]

When I was making my own salt water for hatching I used a hydrometer to make sure the concentration was correct. That's the best way to ensure you don't over/under salt.