What would cause hair or blanket algae to die?

[SEKCOBRA]

Hi all
I had sting algae develop in my stream and waterfall to a point you could not see any of the stream bed or the surface of any rocks in my waterfall. I pulled a little off one day but in the process pieces wound up in the pond floating around. In the next two weeks or so all the algae in the stream and on the rocks disappeared. Great. But then the water in the pond went green. Im guessing the algae that died fed the algae bloom in the pond. All parameters are good. PH is on high end 8.6 to 9.0. KH 150 Ammonia 0 to 0.25 Nitrite 0 Phosphate 0.25 Don't overfeed. Pond gets a lot of sun. Have some plants but not enough to make a difference yet. any ideas why the die off? Any ideas how to clear water without chemicals or a UV? some say barley straw?

 

[Mmathis]

I think you answered your own question. Maybe the string algae died off because of a lack of nutrients, but then that dead material spawned the new algae bloom.....? IDK, just a guess.

 

[MitchM]

There's a phenomenon called allelopathy.
It's a term for chemical warfare between organisms.
It's pretty cool.
https://en.wikipedia.org/wiki/Allelopathy

 

[MitchM]

...Any ideas how to clear water without chemicals or a UV? some say barley straw?

Once you get your salinity down below 0.1%, test your water and we can go from there.

 

[SEKCOBRA]

Once you get your salinity down below 0.1%, test your water and we can go from there.

Ok thanks. may take a while.

 

[SEKCOBRA]

Ok thanks. may take a while.

0.5 by the way.