Small green build up on soil of new plant?

This is my first grow, its been about 8 days since ive had my plant (its getting pretty big ) ive noticed that in the plants soil there is a small build up of some green 'something'. looks like algee

im thinking the soil is molding. i recently placed some 'biofert' fertilizer and its started going green

i cant take pictures due to no camera.
what do i do?

take the shooting out and replant it? (wouldnt that kill it?)

put some form of herbicide in the soil? (i cant afford any shop herbicides)

any ideas?

i think im adding too much water for my seedlings

It's algae, you are using too much water. What I do is grab a bag of Pearlite and put a layer of that atop the soil, keeps that and bugs away.

Water twice a week in veg, thrice a week in flower.

It is a kind of mould mossy kind of growth caused by the heat and moisture hitting the soil.Nothing to worry about happens alot in hyrophonic grows when heat hits the top of the cubes.Get hold of some white reflective plastic and cover the top of the pots but make sure that you put some small holes in the plastic so the roots can breath.Other than that just scrape the top 10 mm of soil of and replace with new soil.It is good to put a small ammount of dry soil over the watered plants any how this stops the plants drying out too fast makeing less waterings for you.But unless it is effecting the plant don.t worry.This normaly happens if you are watering too much and the temps in the g room are a little high.Cut the watering down to once twice aweek max if you are haveing to water more than this the plants probebly need re potting.