Chemicals can work as a quick fix but you have an underlying problem. Too much phosphates in there, most likely. Are you topping it off with tap water? Run off water from the grass? Over feeding?
It may not be fixable if it's run off. Physically clear it out, hit it with snatch of chemicals and install a filter with UV and it'll run crystal clear.
The problems it can bring are removing the oxygen from the water and, if it dies suddenly and isn't removed a huge spike in nitrates, them ammonia, which will kill livestock.
Eta: if plants are dying it's releasing phosphates and organically allowing more to grow. Physically clear a ton out.
well done and thank you for creating an excellent newt habitat
that might not be the response you expected but newts need all the help they can get .
can we have photos please?
if you want a "clean" pond a wier in a fast flowing cleanstone river is quite and effective and provides a different type of habitat for other critters
Perhaps others can confirm, but I think barley straw is used to get rid of blanket weed. Think it absorbs the things that cause it to form and in addition it is a non-chemical method, so shouldn't upset the newts. Agree with what all the others have said too.
We dug a garden pond and newts appeared the following spring when there was very little in it. We have very little water up here, and think we intercepted them on their way to their former pond. We have had them ever since.
||Barley straw will prevent regrowth of the sort that makes the water green. It's not so hot against stuff that's already there, or the macro algae.|
I know some people who swear by barley straw, and of others who swear at it. But I think it has to be worth a try as long as you can get inexpensive supplies.