"Keng" wrote

I have the same thing happen with my cardinals. Although the only
other fish in my tank are the SAEs (4).

I wish I could find SAEs around here. All the pet stores have are flying
foxes and false siamensis, neither species being especially useful in my
case.

I just have to make sure the surface skimmer is on cause I
dont have an air pump. Surface skimmer seems to help.

My Fluval 304 filter breaks the water's surface decently enough. But
apparently it's not quite enough for the neons, assuming the lack of oxygen
is indeed their problem. Right now, with the low amount of light my plants
get, not enough oxygen is produced to compensate for the CO2. I might stop
injecting it util I get more lamps.

Thank you for your reply.

Francois