Cardinal Fish Dying Quickly

[nspringle]

Good morning everyone,

I am batting an issue which I just need advice on. The tank is a 40G breeder and has been running for 4 weeks now. Tested the water before adding fish which showed the cycle was complete. Adding in plants recently and a dozen cardinal tetras. Fast forward to this day I am down 5 cardinals and counting daily. I tested the water today everything checks out PH 7.2, Hardness 75, Nitrite 0, and Nitrate is just slightly showing 5. Temp is sitting at 77 degrees. I currently have bog wood as the driftwood of choice, eco-complete, and gravel as the substrate. The filter is an aqua clear 40.

I am seeing free-floating particles which can be a small breakdown of organics in the tank I am gong to put some filter floss in the filter to capture that. 

Any thoughts or advice on the matter, I haven't had an aquarium in 4 years so getting back into it has been a little bit of a learning curve. 

 

[Lennie]

Cardinals are almost always wildcaught. They are quite fragile for that reason in my opinion.

what is your ammonia readings? How did you cycle your tank? What were the symptoms of the dead ones?

The nitrate u are reading might be coming from ferts and your tank may not be cycled. 
 

without introducing established filter, it is kinda hard to cycle a tank in 4 weeks tbh. Could you explain your cycling process in detail?

it is also likely your bb couldnt handle 12 cardinals at once.

[nspringle]

I tested prior to adding fish or anything. The tank was started with fritz zyme. I just allowed the tank to sit with dritwood and eco complete for the 3 and half week. Tested and seen the cycle was complete based on the reading. Then I began adding the fish and plants that fallowing week. 
 

I do not have any ammonia test strips, I am referencing any reading from the aquarium co-op test strips as well. I am going to a local fish store today to ask for testing just to be safe, and buy more bacteria to let the tank run a while longer. 

[Mmiller2001]

Grab a bottle of API Quick Start while there. I wasn't a believer until recently. Great stuff, added 52 fish and never saw ammonia or nitrite. 

[Lennie]

On 5/13/2023 at 6:34 PM, nspringle said:

I tested prior to adding fish or anything. The tank was started with fritz zyme. I just allowed the tank to sit with dritwood and eco complete for the 3 and half week. Tested and seen the cycle was complete based on the reading. Then I began adding the fish and plants that fallowing week. 
 

I do not have any ammonia test strips, I am referencing any reading from the aquarium co-op test strips as well. I am going to a local fish store today to ask for testing just to be safe, and buy more bacteria to let the tank run a while longer. 

you need ammonia source for bottle bacteria products to work

So basically if you haven't added any ammonia source, it can't be cycled really just by pouring in bottled bacteria

[nspringle]

I understand your logic, so adding the fish has helped begin the cycle with this ammonia source and a little bit of fertilizer. I’ll go to the store today for testing. That can be the big reason why the fish are dying slowly and the rest strips showing decent results.