So when you observed your tank today, you encountered oil on the aquarium water surface...So yes as you may have thought, it can be dangerous for your tank. So this is a simple tiny guide to tackle this problem.
What is it?
The oily layer is a protein layer that does not mix in water and thus keeping floating on the surface. It may come from
your hands when you dipped your hand in the tank,
the fish food which contains proteins and when you overfeed the protein from leftover off comes out
new filters have been oiled for their motors, so a new filter can cause it
or when you keep a dead fish in the tank for a long time.
Is this safe?
Not completely. A small amount of thin layer is just okay and will disappear in few days. But if you notice a thick layer with air bubbles trapped in it...it is dangerous.
The layer will stop gas exchange causing suffocation for the fish, it also stops light from getting to your plants.
How to remove this?
- Manual removal: This can be done with paper towels/ tissue paper. Dip the tissue in the tank and it will absorb it up. But you will need to do this frequently.
Or you can take a cup and slowly remove the protein layer.
Surface agitation. Install a powerhead and increase the water movement.
- Surface skimmer- A device called the surface skimmer is super useful for situations like this. Install it and the layer disappears in minutes...
Also, it helps to distribute air and heat evenly throughout the tank.
Concluding, this layer won't give you much headache, just follow these steps and you are done.