Edexcel exam board Algal Balls

Peter Sigsworth

COMMITTEE
Is 30ml great for a starting batch or would I need more?
Yes, as you will culture it up - tip into a large container with water either rain/distilled/deionised or tap safe water add a few drops of baby bio/ferilizer and then aerate constantly on window sill for a couple of weeks
1674205917451.png
Go to the start of this thread and read through the tips
 
I started my second attempt at culturing algae a couple of weeks ago but I've hit a problem. The first two weeks it was going really well and the solution was starting to become a darker green but this week it seems to have just started separating and sticking to the sides. Over the weekend it had completely separated (like it was just clear liquid with algae just sitting at the bottom of the flask). I've shaken it and turned the air pump up to max but it seems to still be settling/sticking to the sides. I'm not sure what I've done wrong :(
 

Peter Sigsworth

COMMITTEE
I started my second attempt at culturing algae a couple of weeks ago but I've hit a problem. The first two weeks it was going really well and the solution was starting to become a darker green but this week it seems to have just started separating and sticking to the sides. Over the weekend it had completely separated (like it was just clear liquid with algae just sitting at the bottom of the flask). I've shaken it and turned the air pump up to max but it seems to still be settling/sticking to the sides. I'm not sure what I've done wrong :(
You do get that - just keep trying to break it up - I use the aerator by moving the stone (on full bubbling) across the sides to dislodge - it should recover if you regularly keep doing this
 
I started my second attempt at culturing algae a couple of weeks ago but I've hit a problem. The first two weeks it was going really well and the solution was starting to become a darker green but this week it seems to have just started separating and sticking to the sides. Over the weekend it had completely separated (like it was just clear liquid with algae just sitting at the bottom of the flask). I've shaken it and turned the air pump up to max but it seems to still be settling/sticking to the sides. I'm not sure what I've done wrong :(
This happened to me, the way I fixed it was by replacing the air stone (although you could try cleaning it)
 

Peter Sigsworth

COMMITTEE
This happened to me, the way I fixed it was by replacing the air stone (although you could try cleaning it)
Good call - it is common for this to happen or even not have a powerful enough pump - the bigger and deeper the vessel the stronger the pump required. With 5L demijohn, I use a Tetra APS 400
 
Good call - it is common for this to happen or even not have a powerful enough pump - the bigger and deeper the vessel the stronger the pump required. With 5L demijohn, I use a Tetra APS 400
I'll try cleaning the air stone because it does seem to be worse in one of the flasks. I do have the same pump as you and the volume of my culture is around 1.5L at the moment (split across two conical flasks). The first time I tried to culture I put the 30ml starter straight into 5L but it just never seemed to go any greener so this time I've put the starter into a smaller volume to try and make myself 200ml of concentrate that I can then put into 5L like you said you do when sub-culturing.
 
Top