What can be causing my compost to have this green algae to form i have been carefull with the watering, in some cases seeds have failed to germinate it is all bought in compost I have used the same sort other years without any problems.
I have used it for all types of seed sown in the greenhouse ventilated well when it gets warm.
Its a common problem Peter. The compost is too wet and you need good ventilation.The increased ventilation will stop the build up of condensation which wets your compost and creates the problem.
I use peat free compost and it always seems to look bone dry and cracked, but if you dig your finger beneath the surface it is nice and moist. I think it's very easy to over water peat free compost. I have been hardly watering mine at all.
Thank Edd I for got to say I have 2 window missing they got blown out and smashed in the strong winds we had last month, I am still waiting for some new ones, I am woundering if that might be one of the problems as it would get very cold at night.