Edexcel exam board Growing Algae

Last time I set up my algae it grew really well and I managed to make some algal balls with it. I retained some of the original culture to start again and it grew well again but eventually all died suddenly.
I am not sure if I overfed/underfed/kept the same culture going too long!
How often do people add feed and how long would you all keep a culture going without starting afresh with a subsample?
 

Peter Sigsworth

COMMITTEE
It's usually over feeding. They will grow on distilled water which gives you an idea of how little food they need. 5ml baby bio in 5L. And no more for a few weeks then may be a few drops after that
 
It's usually over feeding. They will grow on distilled water which gives you an idea of how little food they need. 5ml baby bio in 5L. And no more for a few weeks then may be a few drops after that
mmm don't think i overfed it then - was more worried I had underfed it! Wonder if I should have subcultured it - do you think algae can get 'overcrowded'?
 

Peter Sigsworth

COMMITTEE
mmm don't think i overfed it then - was more worried I had underfed it! Wonder if I should have subcultured it - do you think algae can get 'overcrowded'?
Well not really but if they die then you'll get them rotting at the bottom releasing toxins which will kill the rest.
 

Peter Sigsworth

COMMITTEE
mmm that makes sense. will not leave them that long in future. Thanks algae guru!
I have found from my tropical aquarium days that it is much easier to keep things alive in the bigger tanks as the larger volume of water helps to nullify any fluctuations in the solution pH and nutrient levels. Hence I use a 5L demijohn, I then don't have to be so careful with the nutrient quantity or more frequent sub-culturing.
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Note - on West facing frosted window ledge all year round even works in winter with no artificial lighting.
It is really important to get a powerful pump so the algae remain in solution and don't stick to sides or settle out.
 
I have found from my tropical aquarium days that it is much easier to keep things alive in the bigger tanks as the larger volume of water helps to nullify any fluctuations in the solution pH and nutrient levels. Hence I use a 5L demijohn, I then don't have to be so careful with the nutrient quantity or more frequent sub-culturing.
View attachment 6431View attachment 6432
Note - on West facing frosted window ledge all year round even works in winter with no artificial lighting.
It is really important to get a powerful pump so the algae remain in solution and don't stick to sides or settle out.
I think I may need a more powerful pump. I have them in a 5l demijohn but do have to keep giving it a shake as the algae tends to settle a little.
 

Peter Sigsworth

COMMITTEE
I think I may need a more powerful pump. I have them in a 5l demijohn but do have to keep giving it a shake as the algae tends to settle a little.
A Fluval Q2 should be big enough. I have an old one on my demijohn which isn't made anymore, but I use the fluval Q2 on my home aquarium and it will easily mix a demijohn full.
 
A Fluval Q2 should be big enough. I have an old one on my demijohn which isn't made anymore, but I use the fluval Q2 on my home aquarium and it will easily mix a demijohn full.
That's what I've got, but it still settles out / sticks to the sides after a few hours :( Do you think the type of airstone (or no airstone) would make that much of a difference or have I got a dodgy pump ?
 

Peter Sigsworth

COMMITTEE
That's what I've got, but it still settles out / sticks to the sides after a few hours :( Do you think the type of airstone (or no airstone) would make that much of a difference or have I got a dodgy pump ?
I found the air-stone got clogged over time and began to loose it's effectiveness - so change it for a new one, see if that works.
 

clairelucas

COMMITTEE
On a positive note, the algae that grew over the summer appears to work well, but..
my pretty feeble pump (aquarium type pump) only seems to provide enough pressure to feed air in if resting a couple of cms only beneath the surface, so I question if its really doing much..
In a moment of clarity, i've now attached the air outlet from my dymax vaccuum pump (continuous flow, not the one for bell in a bell jar), and its got fabulous air pressure (as you'd expect).
Given the massive difference in price of the two types of pump, I plan to use the vaccuum pump for short periods every day (leave the tubes insitu, but detach the pump for the majority of the day), as I don't want to risk breaking it from continuous use.
Is my thinking about right? Or is there a glaring mistake looming on the horizon..?
 
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There is a mix of nutrient ingredients available on the SAPS site (a bit fiddly as the quantities are so small), CLEAPSS have recommended Baby Bio as an alternative, I've kept my culture growing using Phostrogen, a new supplier is recommended on the CLEAPSS Bulletin, Darwin Biological for algae.
 
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