Help!!! 5 dead fish

in 4 days!! the departed include 1 panda barb, 1 emerald cory, 1 bala, 1 green tiger barb, and 1 albino pleco. The remaining are 5 green tiger barbs, 2 plecos, 1 bala, 1 red tail shark, 1 clown loach, 1 emerald cory, 1 pictus cat.
they didnt display any signs of sickness that i could tell, but ive never had a disease in this community. Dont really know what to look for as i have only been fish keeping for about a year.
water parameters are good unless ive overlooked something, zero ammonia, zero nirIte, 20 nitrate, 74 degrees, 7.4 ph. bio filter working good, carbon filter changed regularly, regular water changes with dechlorinator. clear water.
recent additions to the tank are: plants, 2 emerald corys (now 1)
Help me!! i hate waking up every morning to another dead fish.
tank is a 30 gallon
Help!

since your tank is already matured and your WC process sounds normal, did you QT the new fishes before adding them to main tank?

how do you keep the PH above 7?

didnt QT. I dont use anything to alter ph, thats just where it sits right now. just tested the water again, looks about 7.2 ph. absolutely no ammonia. what is going on? did i spread a disease to the other fish from the corys? crap! what is it?

you may have, or may have had a "diseased sleeper" fish. a fish carrying a diseased, but only to affect others at a later time, indefinitely.

the reason "why" i had asked about the PH bit, just wanted to know if you used any products to tamper with PH.

Is there any way to tell what is killing them? any other tests i am missing? the surviving fish are eating fine and seem happy as usual. Any recommended product? Any help from anybody is much appreciated as this is frustrating.
Silk

SilkyT wrote:Is there any way to tell what is killing them? any other tests i am missing? the surviving fish are eating fine and seem happy as usual. Any recommended product? Any help from anybody is much appreciated as this is frustrating.
Silk

a culture test on the passed fishes, may be the most accurate in regards of broad spectrum diagnosis. Im not aware of any commercialize, disease testing kits available freely to the public. may be some other members here can pitch in information.

if, things are fine in your setup...just pay more attention to it, to help initialize treatment. if needed.

Sorry for your losses. It's tough to recommend treatment when there are no symptoms other than sudden death. Is there anything at all different about their behavior or appearance? No gasping or heavy breathing? Scratching or rubbing against objects? Anything like spots, patches, growths on their skin, fins, etc.?

Sorry for your losses. It's tough to recommend treatment when there are no symptoms other than sudden death. Is there anything at all different about their behavior or appearance? No gasping or heavy breathing? Scratching or rubbing against objects? Anything like spots, patches, growths on their skin, fins, etc.?

no, none of these symptoms. the bala did seem lethargic the morning he died though. but thats all we've noticed. i'm so lost

AAAAARRRRGGGHHH. 1 more dead green tiger barb this morning!! I cant take this. I have no clue what is going on in that tank. This cant be happening. Total of 6 fish dead in 5 days.

Wow, so sorry. I've had this happen, and it is hard. I imagine you are performing extra, large water changes. If not, do so. Maybe something landed in the tank, maybe the water treatment plant was flushing something during your last water change, etc. I would also try a UV sterilizer, if you have one or can get one. It may help and I don't see how it could hurt.

Just a thought, make sure your test kit isn't expired. They lose accuracy as they age.

water changes after every death should help.. perhaps your feeding isnt the best possible.. idk im just pulling stuff outta you know where. GL and hope things worked out for the best.

I'd do a 50% Water change off right away.

Also, thats a lot of fish in a 30 gal tank, might be getting some aggression issues, not sure as I'm not familiar with most that you have in there.

Your tank is just not big enough for what you have in there. The Bala Shark alone will grow to be over a foot long,

I'm guessing what happened is bacteria spike, or new fish might have carrying some Disease. My suggestion is do 50% water change, put uv sterilizer and observe. Sorry for you loss tho...

hopefully your ok after this 3 month old posting ,if not...i suggest counseling

LOL I didn't even notice the date of original post...

I lost 3 awesome fish a few weeks ago.. could not figure out why they were bloating up... lost 1 a week for 3 weeks which included my best looking male hap. Water was ok and all. Then my wife noticed them trying to eat the algae from some frayed threads on a silk plant. One swallowed about an inch before he backed out of it. Stinking silk plant cost me 3 fish.