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.Is this the correct algae for making algal balls please?
I bought a bottle of it. I use about half a lid to 2l of water.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.
I shall have to give this another go following these distructions.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.
I think my windows is North or west? Unsure sorryHi,
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'?