Some folks have had winter-related concerns about their cultures:
1. The bottle will freeze on its way!
This is a legitimate concern. We have tried putting “hot hands” packs and insulating our cultures, but 24 hours in our freezer still partially froze the culture. (Surprisingly, most of the Spirulina survived this, though complete freezing would kill them.) One customer has had a bottle freeze on his doorstep. Please think about this before you order…either make sure that the culture will arrive to a place well above freezing, or wait until temperature are higher…
2. My algae isn’t growing well!
If your culture drops below about 50F at night regularly, it won’t grow well. This is especially likely to happen when culture volume is low, e.g. when you are starting out. The best remedy for this is to put a second heater (generally it can be smaller than the main heater, say 50W), set it to 60F or so, and leave it plugged in – i.e. not into the timer. You should see a significant improvement in growth. If light levels are low, you may improve the growth by adding a white light (see the FAQ for a discussion of wavelengths, but almost any bright white light will help), plugged into the same timer as the high-temperature main heater, so it turns off at night. Spirulina require a day-night cycle to grow well; a cycle of 16 hours of day, followed by 8 of night, is fine.
Good growing, and keep your questions coming…
From the heart of the chloroplast,