Rainbow streaks?

[SuperProofer]

Hi Team!

Another question I didn't see addressed previously: so, last night there was an interesting development in my two super-nano tanks I'm cycling (just over 2 weeks into the process).

I was using my phone's flashlight to check the tank for any visible signs of algae growth (I told you, I have a problem. Lol) when I noticed in the surface biofilm at the top of each tank there was some streaky film. Not the same blotchy shape as the biofilm has been. Additionally, when the light hit it, it gave off an iridescent rainbow glow, kinda like when it rains and the water mixes with the oil and chemicals on your driveway.

I haven't touched the water with the exception of the other day when I pulled out those 2 microscopic black specs (one from each tank). I used the same metal tongs I've always been using (never washed them with soap, just rinsed with distilled). The room isn't used much and they are on top of a tall dresser, so it's doubtful anything got spilled in.

I can't completely rule out it may just have been refraction of my light through the glass passing through the water. But the odd streakiness of the film makes me question that theory.

I'll try to get a picture tonight, but my phone camera isn't that great and not sure I'll be able to capture it. But, has anyone encountered this before? Assuming I just need to be patient and it will clear up?

Thanks!!

[Varanus]

I would definitely see if it goes away/was just a trick of the light, you really don't want to risk there being chemicals in there capable of making colors like that (though it seems very unlikely).

[SuperProofer]

Agreed. Don't want to poison the little guys. I'll keep an eye on it.

[AnotherKevin]

For what it's worth, I've seen biofilm like that in a freshwater aquarium which was healthy (but maybe overfed).

[SuperProofer]

That would be nice! Since there's nothing living in the tank, I haven't put any food in it yet.

[Varanus]

Ya know, thinking back I think I may have seen rainbow streaks at some point early in my tank's life as well. Not sure though.

[SuperProofer]

Well my fingers are crossed that this is normal. For the life of me, I can't think of anything else that could have gotten in there otherwise.