[yoojustin]

I’m curious if you might be able to answer some things I’ve been having issues with. Over the past few weeks I’ve been having some die offs in 29g, two year old tank. I started the tank with remineralized distilled water because our city water tested poorly. Now, salty shrimp is getting to be quite the expense, and I figured I would try to fill a bucket with city water with some surface agitation to dechlorinate.

Here lies the problem, after a few days it develops a strange white film on the surface of the water (pictures below). I’m not sure what it is and if its safe. So instead, I’ve very slowly switched aquarium water to bottled spring water and I’m nervous thats the issue leading to the casualties. I can’t find a water analysis for the bottled water but I did find one for our city water (attached).

So the quesions: what could this white film be? And do you think our city water would be fine to use?

Thanks for any advice!

 

[Oughtsix]

I am guessing that it is biological in nature, most likely algae of some sort or possibly bacteria, maybe yeast. My GUESS is the chlorine has been neutralized and nothing is keeping organisms from growing on the water? We have something simular in the toilet of the spare bathroom. Since we are on well water there is nothing to keep micro-organisms at bay in water exposed to air.

I will be interested to see what others come up with.

 

[bataleon]

This should give you some info mate. 6 Causes of Aquarium Oily Films (And How to Fix it!) - FishLab

I've currently got the same biofilm in my tank.

 

[ElleDee]

Any chance the bucket wasn't totally clean before you added the water?

 

[minorhero]

99% chance its bacteria. Surface agitation will make most of it go away (can put a bubbler in there if you want). Or you can skim it off and use it. It's very very very normal.

Anyway I've never made the leap in scientific terminology between a water report and the things/quantities we care about.

What is the gh/kh/tds/ph of your tap water? Those values will tell the tale of whether you should just switch to tap water.

 

[mourip]

I would ask a neighbor if they are seeing the same thing. If so, I would get in touch with the water company. If not then, I would consider checking your own water system or even your air conditioning. Either way that should absolutely not be happening.

What happens if you use Prime? Another container?

 

[evil8]

I'm not 100% sure what it is, bacteria or protein, but I get this same thing in my tanks without sufficient surface agitation. I've used nano skimmers or adjusted my outflows to get surface agitation. Or more frequent water changes fixes the issue too.

 

[yoojustin]

Any chance the bucket wasn't totally clean before you added the water?

I'm not sure. I did use dish soap and let it dry overnight. Maybe that was a mistake. I also had a lid loosely on top.

99% chance its bacteria. Surface agitation will make most of it go away (can put a bubbler in there if you want). Or you can skim it off and use it. It's very very very normal.

Anyway I've never made the leap in scientific terminology between a water report and the things/quantities we care about.

What is the gh/kh/tds/ph of your tap water? Those values will tell the tale of whether you should just switch to tap water.

Thanks for the info!
Nitrate- less than 20
Nitrite- 0
Gh- 25
Kh-300 or more
Ph- 7.8-8.4
Tds-450

The Kh and Tds seemed crazy high, which is why I started with remineralized distilled.

I would ask a neighbor if they are seeing the same thing. If so, I would get in touch with the water company. If not then, I would consider checking your own water system or even your air conditioning. Either way that should absolutely not be happening.

What happens if you use Prime? Another container?

Haven't tried prime or another container. That's a nice idea to experiment with!