Millions of tiny bubbles

Scrumpy

Large Fish
Oct 22, 2002
214
0
0
London, UK
#1
The water in my fish tank has become saturated with millions of tiny bubbles the last few weeks. At first I thought the front glass was fogging up with algae or that I had a bacterial bloom, but it's not that.
It's billions of microscopically small bubbles rising from near the bottom of the tank. It makes the water look cloudy and spoils it.
I wondered if there was decaying matter in the gravel, but I vacuum it thoroughly every 2 weeks so I don't think so. I've turned off the bubbles so it's just a jet of water from my biolife filter...my plants are ok but I don't think they're the origin of the bubbles. They're not exactly pearling, but healthy enough.
I don't use CO2... ammonia and nitrites 0ppm, nitrates 5-30 depending on when I do a water change.
Any ideas please?
 

Oct 22, 2002
218
0
0
#2
How long have you had this tank set up? It might be air caught in the gravel. Don't worry about it, it means your tap water is probably saturated with oxygen, good for the fish.