I came home tonight and found the following in my 20 gallon:
2 dead Otocinclus affinis (one from my 40 gallon to the 20 gallon and one I just bought last week)
1 Otocinclus affinis that looks like it has swim bladder (still a baby but bought from last week)
1 male cherry barb that wiggles when it swims.
other fish seem okay (4 Brilliant Rasboras, 2 corys and 3 other cherry barbs)
I did a water change this past sunday (5 gallons) and i thought everything was going well.
mostly my cherry barbs have been dying (I replenished 2 2 weeks ago)
i have 1 cherry barb that I saw trying to rub it's body on the gravel.
pH is between 7.6-7.8
i have no live plants but have algae that i've seen the otos eating and supplement with algae wafers.
I have 1 rena-air air pump pumping in bubbles.
my 20 gallon tank is near a gas fireplace (and sometimes I think I smell a little gas but not sure).
My 40 is right near my 20 but more away from the fireplace.
driftwood is available to soften the water and for the otos and corys.
using emperor power filter.
temp is about 75-77 degrees
is it possible the air that is coming into the water is partially that natural gas?