Mosquito larvas?

I have a small pond in the north of Spain. I am a complete beginner in forums and in ponds and I will probably make mistakes in English, so please be patient with me. My pond gets filled in with water from the rain. Now the water is very green which I quite like but it in the surface ther are thousands of what I think may be mosquito larvas. I have got rid of some of them with a net. I am worried in case I get an invasion of mosquitos in my garden. I have heard there are some tablets that they use in America that are disolved in the water and kill the mosquitoes but not the little frogs. Has anybody heard about them? Any other advise? Thanks in advance.

Usually if you have movement on the water surface (i.e. a waterfall or fountain), then they cannot survive into the next phase and will die. Also if you have fish they will usually eat the larva.

they are called mosquito dunks , type that in and you will find them

Mosquito dunks and most other naturl mosquito control products are made with BTI which is a naturally occurring bacteria that is harmless to people, pets and fish, but deadly to mosquito larvae when it is ingested. Another popular product is Microbelift BMC (biological mosquito control)