Bubbles?

[DarthBaiter]

Hello All, 

I noticed all of these bubbles in my fish tank today. What are they and how to I fix the issue?

Thanks! 

[Patrick_G]

Did you add any medication or other chemicals recently? 

[DarthBaiter]

@Patrick_G No. The only things I have used are water dechlorinator and quick start. I also used new fish food and algae tabs by Sera. I also have a 50 gallon Marineland biowheel filter. My tank is a 37 gallon. 

Edited June 29, 2021 by DarthBaiter

[Randall from Texas]

You could use your gravel vac to skim the water surface. I do that after I feed a messy food that leaves a oil slick.

[Phantom240]

Did you just recently do a water change? Running any airstone or co2?

[tonyjuliano]

This is biofilm forming on the surface.  It increases the water tension, preventing bubble from bursting more quickly.  Like when you add soapy solution to water.

You can skim it off, but it’s more of an indication of excess nutrients in the water column.

On 6/28/2021 at 8:26 PM, DarthBaiter said:

I also used new fish food

This is the likely culprit. The new food is probably more protein dense.  
 

Many times fish are reluctant to feed at the same level when new food is introduced.

Uneaten food = more nutrients in the water, which often results in this “slick” you see on the surface.