Questions about Algae Beads

My algae beads did not change color.  What should I do?

 

1. Did you add the diluted carbonate pH indicator? 

If they were the Ready-To-Go version, they came in the indicator and are... well ready.   You will need the indicator solution you ordered "Beads Only".  

 

2. Have you given them some time under a light. 

The carbonate indicator has a buffer (sodium bicarbonate).  If the beads have been in the dark for >24 hours they have respired, and it will take a bit of time in the light for photosynthesis to fix all the CO2 (aka carbonic acid) to bring them up to the pH where color change occurs.  Keep in mind that the pH scale color change is smaller than the actual pH range that can occur with the beads in the solution.  

An analogy would be a person walking across a stage.  At first they were not visible at stage left... then they were seeable by the audience.. and they exit stage right.

 A good light source is a CFL lamp about 2 inches from the bulb.

 

3. Are they dead?  

If they are still a pretty green, they are not likely dead.  If the beads turn pale yellow green they may on their way to the next world.  

If you believe you have committed algae murder, these are the most likely weapons that will be discussed at your trial.

Heat:  Temperatures above 38C (or 100F if you are using the units from the Ancient Ones) are bad for the cells.  The culture will turn to a pale green after a day or two. 
Too much light:  Direct sunlight will kill them, in about 10-20 minutes. Simply there are too many photons for the algae to process.  They get overloaded with energy and go into full photo-protection mode to waste the light (xanthophyll cycle pigments and B-carotene).   They can do it for a few minutes, but after a while its just too much and the photons destroy their photosynthetic pigments. 
Freezing and Cold:  Freezing can kill the cells.  Please do not store them in the freezer :(  chilling to 1C will not kill the algae, but it will slow their metabolism.  Lower temperatures slow rates of respiration and photosynthesis by 1-5x.  If it is cold, expect slower pH change, and try not to overload the cells with too much light (see too much light above).  
Bad singing:  Do not Rick Roll your algae, we can not emphasize this enough.   They love show tunes such as songs from Hamilton, classic rock from Queen or Pink Floyd are ideal, and seem to respond well to Tom Petty.