Red Tail Barb need help pronto!!

[Niles6705]

ok so i have a red tail barb and a albino rtb in a 55 with Blood parrot cichlids (or whatever made up name u wanna call them) lol

so i fed them about 6 hours ago and everyone was fine, then an hour or so ago i look and the albino is dead and the rtb is swimming upside down,
but bp's are fine, even the babies

i hurried and switched him into another tank with ropefish and checked the leves thinking that was it because i slacked a little on water change, but all were at 0 ish ppm.

so i did a water change neways and now im totally confused because the rtb is totally fine in the other tank swiming all around and has taken food...i need to find a reason so i don't sit waiting for the bps to drop dead

please help!

 

[12 Volt Man]

not sure.

your ammonia and nitrite levels are zero right? and your nitrate is what?

the only time I have seen large tinfoils just drop dead is after smashing into the glass at 50 miles per hour.

but you lost one fish and the other was swimming upside down which means it wasn't injury.

swimming upside down is usually the last step before death from oxygen asphyxiation.

is your filter working fine? double check your ammonia levels as high ammonia burns the gills and prevents oxygen uptake.

 

[Niles6705]

yeah zero on amonia and nitrite, using api kit so between 0 n 5 but just darker yellow, not red/orange at all, kinda like a morning pee lol
only thing i have changed at all is new carbon 2 days ago, filters are running fine and now im just so lost
i hate when i can't find a reason, i had a bichir die over a year ago outa no where when he was with 6 others and it still bugs that heck outa me

 

[Niles6705]

also suprised bout how he was IMMEDIATLY fine when i moved him, i mean dropped him in he stayed upside down for like 7 seconds then started swimming n darting n hasnt stopped since

 

[Niles6705]

bump

 

[12 Volt Man]

do a pH test. in the past I have had issues in heavily stocked tanks where the pH has crashed (old tank syndrome).

being that the parrots are derived from south american cichlids, it could explain why they were fine but your barbs were not.

moving them into another tank (with a higher pH) and having them be okay would also make sense.

check it out. if its in the 6.0-6.5 range, that could do it. I have found that barbs are quite sensitive to lower pH's.