is this Cyono?

[Corwyn]

I don't know if it's the heat or waht but overnight I developed somekind of
thick film algea on the sand in my tank.

I've been having a bit ofa problem with hair algea but last 48 hours or so I developed a very dark green(maybe) or black film algea. It's prety think, to the poing where I can pick it up and it stays together. Covered in bubbles.

The only thing that has changed in the tank is that I switched from using kalk to pickling lime.

nitrate 0
nitrite 0
phosphate < .3 according to Seachem test ( though I have to question this as the result IS yellow, but it doesn't even come close to the color on the chart)

Ph 8.4
ka 9
Calk 425.

The only other thing I can think of is my bulbs need to be changed?
I have 3 400W Hamilton 14Ks. They are about 10 months old.


Corwyn

 

[jackie]

Hmm, well cyno is usually a reddish/brown color. Maybe you can throw in a phosphate sponge and see what happens? Are you using RO/DI? Check the water with a TDS meter and see what that reads....