Algae question

Discussion in 'Supporting Biology' started by Hands Solo, Mar 15, 2018.

  1. That's what I use. Depending on how much time you have you can use it as is, but it won't make that many balls, or you can grow it on so you have lots of lovely algae - this can take a while though if you don't have a bubbler.
  2. Thank you Snailo.

    The teacher has given me plenty of notice so I'll have time to grow it on (I'm trying hard to encourage thinking ahead and she is pretty good). Just wanted to make sure I buy the right stuff.

    Have a good weekend.
  3. Thats what I used too, I feed it with miracle gro, had my culture sat on my window all year now. The practical doesnt work that well.
  4. Thank you Jburns.

    How much miracle grow to water do you use please? I have a bag in the shed I can use and it will mean I don't then need to buy one of the chemicals given in the recipe.

    I have warned the teacher that reports on this practical aren't favourable but we'll still give it a go.
  5. I use 'babybio' or hydroponics nutrients - I guess a couple of spatulas of miracle grow in 2L will do.

    I find there are five (six) things you need to get right to a get a result in an average double lesson:

    1. The algae need to be as concentrated and as large a volume as possible - I default to my wine making days and culture the algae in a 5L demijohn on the window ledge (I keep one on the go constantly). After a few weeks of aeration I allow it settle for at least 3 days, then syphon off the excess clear liquid, I then pour the algal soup into a large measuring cylinder and let it settle again for a few days, decant off the clear layer. Make the balls from this.
    2. Use small bijou culture vials (7ml max) - the reduced volume of bicarbonate indicator means the balls have a smaller volume of indicator to change and this speeds up the process.
    3. Make sure the bicarbonate indicator is made up with distilled water and has been aerated for a day or so before - so the concentration of dissolved CO2 is equivalent to the atmospheric CO2 - the colour will be in the mid range of the indicator so it will be easier for the balls to change the colour either way.
    4. Use as many balls in the vials as you can get away with - the more balls the quicker they will work - all you need to see is enough clear liquid at the top to get a colour reading. (don't forget to shake the vials regularly to mix the indicator).
    5. Get a very bright lamp - the brighter the quicker photosynthesis will work - I use a D7S J118 30W LED work lamp (warm white) - equivalent to 300W Halogen. If you use Halogen then you can get up to 400W but need to deal with the heat produced by putting a water barrier between the specimens and the lamp. Avoid looking into the direct light, so have it shinning away from the students if you can.
    6. Another tip to speed things up is to get the students to load their vials just with balls in the previous lesson (as this takes them ages) add a bit of distilled water and leave them by the window. When ready to run the experiment all they have to do is decant off the water and add the bicarbonate indicator.

    Don't forget that you can recycle the algal balls by emptying them through a sieve, washing and storing in distilled water in the fridge - they last for months.

    Happy photosynthesis :)
    skaur and Colly like this.
  6. Thanks for all the info Peter, as I've not done this before I'll make good use of it.

    After some discussion I think we're going to look into lighting.
  7. I bought a bottle of it. I use about half a lid to 2l of water.

    I shall have to give this another go following these distructions.
  8. Shannon

    Shannon Shannon COMMITTEE

    The Algae we have is doing brillant!

    Haven't had to do a thing... we assumed it would last a week and its still going from November time...

    They seem to love a north faced Window and we don't have the top covered..

    Rather proud of it :)
  9. Hi,
    I am about to try and culture S. medium for the first time so I can have a go at making some algal balls - wish me luck!!!
    We have lots of window sills where I can put my container of algae while it is growing but wondered if it has to be a north facing one? We have lots of big windows facing east and west but only a couple facing north and these have an opaque covering on them.
    Is north facing suggested to prevent the alga getting too hot and 'cooking'?
  10. Shannon

    Shannon Shannon COMMITTEE

    I think my windows is North or west? Unsure sorry
  11. south facing would be best, depends on the view of the sun though.
  12. I've had a culture going for about 18 months now - it's in front of a north facing window and has a lamp on it 24/7 along with an aerator.
  13. Mine is west facing and no need for a lamp - been going for over a year now (with 2 monthly remove sample discard the rest and re-inoculate in fresh water plus fertilizer). Look to the left at my profile pic
    Lisa J likes this.
  14. How do you dispose of the excess algae please?
  15. compost
  16. Thank you folks.

    I'm determined to make a better job of keeping it going next year.
  17. Well thanks for the tips folks. Have now got a demijohn set up on a south/west facing window sill. Hoping for super green pea soup when I come back after half term.
    Just hoping the cleaner/caretaker notice my 'please do not switch off' sign!!!!!