[billsreef]

Sounds like your getting a good start. As for your phyto, did it get nice a dark looking before it yellowed? Based on the time frame, I think it peaked and started dieing back. Usually it only takes a week from inoculation to a culture being ready for harvest. At this point you really need to harvest regularly to keep the culture in the exponential growth phase. Depending on how far gone it is, and what phyto it is, you might be able to renew that culture by putting a couple of ounces into a fresh bottle of medium.