My phytoplankton keeps crashing right after I start a new culture. It looks good for a day or two then it turns a light yellow color and never develops into the usual green color. My initial cultures did well for about three weeks and then the crashes started. I am using and reusing 2L soda bottles, 1ml of micro algae grow, SG of 0.017 and temp of around 68. Thanks for your help, I am getting very frustrated!! My clownfish just laid eggs and I am afraid that I will not have enough phyto to keep the rotifers going.