I have restarted this game three times now and if I am honest its really beginning to _bug_ me.
I seem to be doing everything ok, I get the food problem sorted an update to the trees when the green algea comes but I cannot get rid of the green algea no matter how much I look with a master farmer, am I doing anything wrong ? or looking in the wrong place.
The furthest I have got is the two huts built, the dam, fire, the sharp intruments made and started to cut back but only got to 80% complete, crops coming every 300 and odd so minutes but then everyone died because there wasn't enough food
Please help or give me a few pointers to help me on my way

You are going at it the right way. But you have to have a certain tech level.

You're on the right track with the master farmer, but you need a certain tech level first ...

you have to have food level 3 and a master farmer, you have to let them get at least 10 yellow fishes, i think, i had 5 master farmers and i put them to do and i finally did it, your best bet is to have 2 or 3 master farmes and do it a few times.

good luck

What do you mean a certain tech level, I got level 2 farming, level 2 building, level 2 tech and level 2 foresty kinda thing but I keep running out of food but cannot get my tech points up enough to get the level 3 farming

Well you don't have the right tech level of the right tech just yet. Unless you have a lot people, you should be able to hold them off until you get what you need.

No igottapi4, she does not have the right tech to solve it yet.

i know thats why i edited my answer.

Ok, well it was not edited when I wrote it. Sorry. And we are trying not to give out too many spoliers just yet.

Make sure you build the dam as soon as you can. That gives you a better chance of making it through. Looking for mushrooms can be important in this game - even a life saver - just as it is in VV1. Any duplicate collectibles you spot while looking for mushrooms also help your tech points.