What's this white film on top of water?

[dfinn]

Hi Everyone,

My tank has started to produce this weird particulate film on the surface (see picture). If you try and mix it in it just forms white particles within the water. I have to skim it off the surface to remove it. I was wondering if it was something to do with my EI ferts, could my water be supersaturated with them so they are unable to dissolve? Or is it something else?

 

[zozo]

Most likely a protein film with some bacteria, tho yours is looking quite heavy.. Me also i have it sometimes, not always and not this much, sometimes it's there for days and then it goes again by itself. Plants can cause it, excreting excess protein.. Usualy when i see it comming i up the filter cleaning and do a big waterchange the day after, this always helps a bit to keep it under control. It comes and goes in my case, once in a few months it's there for a few days or a week or so. I have no idea why and how this so suddenly is triggered for no obvious apparent reason. Beats me, maybe someone else can tell..

 

[Chris Jackson]

I've had some instances of a this when using EI though not as heavy as you seem to have it. Reducing the EI dose helped but I now just use an all in one recipe from the James's planted tank of site and occasionally some Fe instead of EI and such films are consigned to history, unless I overdose the Fe.

 

[ian_m]

It organics from the plants as they are adjusting to CO2 and lights and EI. You can soak it up by floating a sheet of kitchen towel on the surface. Or run and air stone at end of CO2 period, that's what I did. It will after a week or two stop forming.