Clear Green

can anyone tell me how to clear green water in my pond i have tried barley straw flakes and chemicals?

I cannot afford to buy uv filters and things like that

The key to clear water is to achieve a balance between the various inhabitants. The plants absorb mineral salts and carbon dioxide from the water and in the presence of sunlight, create food materials and oxygen. The fish absorb oxygen through their gills; apart from their aesthetic attraction, they feed on such pests as water-lily beetles,aphids and caddis flies. They also fertilise plants with their excreta.
So long as the plants- particularly the sub-merged oxygenators get plenty of light and have to compete for minerals, the microscopic algae that make the water murky will have little chance to thrive. On the other hand there must not be too much light, in relation to the number of oxygenators. It is vital therefore to carefully work out the number and size of the pools inhabitants.
There cannot be too many under water oxygenators, especially in the first year or two; after that any surplus can be removed.
But floating and deep-water aquatics (such as waterlilies) must never cover more than about half of the pools surface, so as not to create too much shade.
Murky green water indicates that there are too few under water oxygenating plants to compete for the available light and minerals, ot that too little shade is cast by water lilies. Correct these causes of imbalance, and then if necessary use permanganate of potash to clear the water.

How To Clean A Green Pool – Part 1 – Swimming Pool Cleaning