HELP! Mysterious "gunk"?

[AllNighter]

Noticed a sort of whitish film developing on the water of one of my betta tanks, I started to get concerned when it began I saw more whitish stuff on his little decoration, so I took everything out of his tank and cleaned it with really hot water and a teensy bit of bleach, then got him a little plant, to help keep the water clear. Thought the problem was solved, but its back and worse than ever! It developed so quickly! Help please, what is this stuff, and how can I get rid of\prevent it?

 

[Demeter32]

Is this a newer tank? Can you test for ammonia, nitrite, and nitrate then post the results? Does this tank have a filter and heater?

The film on the surface of the water is bio-film, a thin layer of proteins that build up in stagnant water (no surface movement). Usually the movement from a filter prevents the build up of this.

As for the stuff on the ornament, it doesn't appear to be any sort of algae but perhaps diatoms are the culprit. Diatoms are most common in newer setups and they usually go away on their own after a while so long as the water quality is kept in check.

 

[Toney]

Mycelium it won't hurt anything, ive had some in a new setup

 

[AllNighter]

Is this a newer tank? Can you test for ammonia, nitrite, and nitrate then post the results? Does this tank have a filter and heater?

The film on the surface of the water is bio-film, a thin layer of proteins that build up in stagnant water (no surface movement). Usually the movement from a filter prevents the build up of this.

As for the stuff on the ornament, it doesn't appear to be any sort of algae but perhaps diatoms are the culprit. Diatoms are most common in newer setups and they usually go away on their own after a while so long as the water quality is kept in check.

I suppose it's newish, it's about 2 months old? I can test the water, but I'll have to go buy the test kit thingie. It's a pretty small tank, 3.5 gal. and it doesn't have a filter, or heater. It's kept near a lamp designed for that purpose.

What's confusing is that my other tank, kept in the exact same conditions, has perfectly clean water?

 

[NickAu]

It's kept near a lamp designed for that purpose.

Can you give more details about this lamp, I cant see how it would keep the water temp stable, and what about at night?

 

[AllNighter]

Can you give more details about this lamp, I cant see how it would keep the water temp stable, and what about at night?

Yeah sure, it's really cool! It's like a little shelf for the tank, and the back "wall" of it has these heat lamp sort of bulbs going across. You can turn them up and down, I keep it at 79, 80 degrees. At night you turn that part off and flip the black light on. It doesn't bother them, so I don't know if they can actually see black light or not?

edit-
It's made for smaller tanks. obviously. XD

 

[NickAu]

How often are you changing water?

Can you post a photo of the tank?

 

[AllNighter]

How often are you changing water?

Can you post a photo of the tank?

25% twice weekly, normally. Since this gunk started showing up I've done 50%.
I can get a photo of the tank, no problem, but not until around 11:00 AM tomorrow, I should be off work by then.