I've been farming freshwater fishes. After some time, i found some green algae grows there. When the algae dried, it looks like nori (which commonly used for sushi wrapping).

So, i wonder if those algae edible for human. Are the algae safe to eat?

Here's the picture:

enter image description here

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    $\begingroup$ Can you advise where you are at (not an address or anything, just what state/region/country something like that)? $\endgroup$
    – L.B.
    Oct 27, 2016 at 15:12
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    $\begingroup$ I live in Indonesia $\endgroup$ Oct 28, 2016 at 3:30
  • $\begingroup$ Don't risk it. However to me it looks like sort of filamentous chlorophyta; still it is impossible to identify without microscopy. $\endgroup$
    – user25568
    Dec 14, 2016 at 5:50
  • $\begingroup$ If you really would like to eat it without causing you problem, your best chance would be to eat a very small amount first, get accustomed to it and gradually increase the amount you eat. Given that the pond is relatively clean :) $\endgroup$
    – y chung
    Jun 28, 2017 at 13:03
  • $\begingroup$ Looks like blanket weed (various green algae) to me. $\endgroup$
    – Alan Boyd
    Jun 28, 2017 at 18:17

2 Answers 2


I came across a this Wikipedia page which said blue green algae from ponds can be used as dietary supplement (in tablet form).

Many other articles on the internet like here suggest it is included in many diets in many places across the globe.

However, without proper regulation one can include a heavy metal contaminated vegetable to their diet which is detrimental to health. Furthermore cyanobacteria are known to produce toxic substances known as microcystins which can cause damage to human organs as well.

So unless you are certain of the biochemical balance of your pond I would recommend not integrating it in your diet. Rather you can find commercially available ones which your local regulatory authority(s) recommend for dietary purposes.


First off: Don't risk it

I'm not an ecologist but I believe the type of algae you are holding tends to be cyanobacteria.

Cyanobacteria make all kinds of toxins, check the first table in this article.

Some cyanobacteria are eaten like Arthospira (commonly called spirulina) but I would not eat any random filamentous cyanobacteria. They also tend to be quite hard to digest so at best you will have increased your dietary fibre level and at worst ... well make sure your sanitary facilities have enough capacity.


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