help with stuff on my sand bed

[craig_will2513]

hello all. iv just got rid of what i think (going by you guys advice) was diatoms got a yellow check goby to clear my sand bed of it for me. now i have a strange new problem i need help with if anyone is willing to shed any light on it.. well i now have a very pale green stuff growing on my sand and the sand is all clumping together and forming what looks like little bits of gravel and id like to know what it is.. although in the pic its hard to see the colour but its very pale green thanks in advance guys

 

[ccCapt]

Hard to tell from the pic, but by your description I would say it's cyano which is cause by excessive nutrients in the tank.