f & e tank (brown scum)

[118roy]

I have noticed that my heating F & E tank as quite a build up of brown scum. I have cleaned the tank but the scum soon returns.
What I am concerned about is that I have a small bore 8mm system and if this scum enters the system it might block the system, should I worry about it or is there some thing I can put in the tank to keep it clean.
I have tried inhibitor but no luck

 

[kevplumb]

try some cleanser then

 

[JohnD]

it might be fungal or bacterial growth if it is on the surface. Corrosion sediment usually lies on the bottom like mud. Bale it all out, sponge it clean and wipe it including the lid and float with bleach. After refiilling add two teasponsful of thin bleach.

Or at much greater expense use Fernox AF-10 universal biocide, like I do (I got the translucent bacterial slime in my F&E, which is disgusting)

If you are going to use a system cleanser (good idea) do that first.