I dove into the BBS and tried the 2 liter bottle method several times. I have to say I was not too impressed as it's nearly impossible to get only the live shrimp without the unhatched cysts and whatever else floats to the bottom. While it did work, I was a bit dissapointed.
So I went ahead and bought the dish from Brine Shrimp Direct to give it a shot. I loaded it up an set the dish on top of my tank. The tank is acrylic with a top and the dish fits nicely between the hood and tank. This gives my a precise 80 degree temp with lighting for the first 7-8 hours depending on what time and refill the dish.
The first batch offry started showing up within 8 hours, peaking between 18-24 hours. I was a bit dissapointed in the numbers, but I was only removing BBS which was the goal. I was able to skim off BBS for a couple of day like this, but of cousre the numbers diminish over time.
I've read about water fresh water changes for each batch, cleaning the dish, etc. but I decided to recycle the water and see what it did to the hatch rate. I strained off all of the unhatched cysts and shells and was left with debris free water, but it was obviously "used" being a bit cloudy.
I used the exact same amount of eggs from the same container and checked the following morning. I have to say, I was a bit surprised at what I saw. The amount of BBS was astonishing. The hatch rate had increased by no less than three-fold. There were so many BBS in the trap that the water took some time to drain through. I seriously couldn't believe it. This continued throughout the day. I could see many of them in the inner circle on the bottom, waiting their turn to move to the center of the dish towards the light.
So I figured what the hell, I use the water again. Surely the O2 levels will be diminished, and the water has to be getting funky and the hatch rates will drop. Nope. They went bonkers again, possibly even more from the previous day. I had BBS coming out my ears and it was more than I could use in a day with 3 feedings. Iused the water one more time with great success.
Yesterday I figured I'd put it to the test and mixed up a fresh batch of water and loaded the dish up. This morning I was back to square one (just like the first time I used the dish) with a moderate amount of BBS, but nothing to get excited about and definitely not 80% hatch rate.
Sooooo, after that book, has anyone else had this experience? What water parameters could possibly be changing that would increase the hatch rate like that? Anyone have any ideas? My only thought is that by reusing the water, there are nutrients left behind by the previous hatch suspended in the water, but why would that increase hatching?
I'd love to hear an explanation on this one.