My Cardinal Tetras are Dying - What's Happening?

[gy960]

But if the cardinal tetras are breed in Singapore farms, not sure if they are reared in normal Singapore tap water (base pH). Then the tetras are used to neutral/alkaline waters.

[o2bubble]

Likely due to ammonia spikes and maybe sudden ph change. Did you let your tank cycle for at least 3 weeks before you add cardinals and you should add slowly e.g. 5-10 at a time and each time let the fishes adjusts to the water temperature first before releasing from the bag? Also, when you change water did you add anti chlorine like seachem prime which neutralizes chlorine and does not produces ammonia based side products? Also, cardinal can adjust to waters from 5 to 8 ph levels, so no need to lower ph although they show best colors around ph 6-6.5. Try to remove ammonia and add some beneficial bateria solutions to improve your waters. Do not keep changing water and let your tank cycle properly first (change <50% once a week is enough). Just my 2-cents worth based on similar experience. Lastly, hopefully some of your cardinals survives at the end. Hope it helps.

[mohgui]

Where did you get your cardinals from? Every suspect are the fishes that have the problem? Are they from a tank of water that wasn't colourless? Probably they were undergoing some treatment when you bought them.

got them from Sea View Aquarium at Seletar West Farmway 2. i got 50 at one go because it's cheaper in bulk. and the guy got the fishes from the inside and not from the display tank. so i'm not sure what colour was the water from the inside tank.

[mohgui]

But if the cardinal tetras are breed in Singapore farms, not sure if they are reared in normal Singapore tap water (base pH). Then the tetras are used to neutral/alkaline waters.

that's what i thought so too... unless the breeding farms conditioned their water. i think i must start to use additives to remove minerals from the tap water.

[mohgui]

Likely due to ammonia spikes and maybe sudden ph change. Did you let your tank cycle for at least 3 weeks before you add cardinals and you should add slowly e.g. 5-10 at a time and each time let the fishes adjusts to the water temperature first before releasing from the bag? Also, when you change water did you add anti chlorine like seachem prime which neutralizes chlorine and does not produces ammonia based side products? Also, cardinal can adjust to waters from 5 to 8 ph levels, so no need to lower ph although they show best colors around ph 6-6.5. Try to remove ammonia and add some beneficial bateria solutions to improve your waters. Do not keep changing water and let your tank cycle properly first (change <50% once a week is enough). Just my 2-cents worth based on similar experience. Lastly, hopefully some of your cardinals survives at the end. Hope it helps.

yes... tank cycled for 3 weeks before introduction of fauna. maybe as what most of you guys mentioned, there could be a spike in ammonia. i have yet to get the test kit to confirm this though.

[bernie]

Consider getting XL size of cardinal tetras, there are more resilient.

[mohgui]

ok... i've done some test to the water and here are the results:

Nitrate - 0.00 ppm
Phosphate - 0.5 ppm
Ammonia - 1 mg/l
pH - 6.8

i've got 4 tetras left and these 4 lasted for a few days already. i guess they adapted to the water condition.

i also added peat granules to the filter. hopefully, it will lower the pH and get it stabilized before i add more tetras.

[gy960]

Ever considered the hardier glowlight tetra?

[mohgui]

Ever considered the hardier glowlight tetra?

i prefer cardinal tetra because of the brilliance of the red and blue against a green background (plants).

btw, how much is the glowlight tetra?

[gy960]

Usually same priced as cardinals or neons. +/- $1 at qianhu.

[itxno1]

Too much would affect the PH and harmful to fish also. It makes the fish hypoxia.
Secondly, too many fish introduced into your tank at once may cause ammonia shoot up to toxic level that cause fish die.

[Dean]

I totally agree that introducing fish at that amount can cause ammonia spike especially when the BB couldn't cope with so much bioload at that time. I recommend adding 6~10 fish at a time and introduce the second batch 2 weeks later. Cardinal tetra prefer acidic water too. I hope you have better luck in keeping them now.

[Merduka]

Hi bros,

Saw this thread and could not resist as well. I hv almost a similar set up... ther bro can kindly confirm the substrate used? I was recommended the light brown pellets (small balls) from Colorful West Coast. This is my 3rd time recycling my 2ft tank - all my tetras died as my 2nd hand eheim started spewing white foam. Fixed that with KY jelly.

My quesru, I noticed the outlet Eheim is submerged? Is this the correct way as mine is above spewing like the Merlion.

Regards
Merduka

[bernie]

Are you dosing fertilizer , flourish excel ? I think cardinal tetra are very sensitive.

[mohgui]

My quesru, I noticed the outlet Eheim is submerged? Is this the correct way as mine is above spewing like the Merlion.

i submerged the outlet because i feed CO2 through it. i'm using the water flow to spread the CO2 distribution.

[mohgui]

an update to my tank; i recently added 11 cardinal tetras (larger in size) to my surviving 4. it's been 4 days already and none died yet. looks like my tank has stabilized. i've also introduced peat into the filter. but the pH level is still hovering around 7. i would like to bring it down further, but if the fishes are happy about it... then i should too

[wcneo]

what soil u brought? some soil have high ph. if the soil ph is those high one, u try what also no use as it will keep push back to it normal ph lvl.
check the soil packing or ask the shop owner. current might be to big but the eheim you have can be tune to slower flowrate.

[chilla18]

I suspect that SeaView cardinal are not properly condition I brought 100 pcs and within 1 month left with less than 20 fish everyday 2-3 cardinal will die.

[wcneo]

when u buy did u see the water colour in the bag? if got colour mean the fish not too good so they add chemical in. u can try at c328 there cheap and good. i last time buy only 1 to 3 die till i change into shrimps tank

[chilla18]

No colour in the water that comes with the bag. Any idea how much is C328 selling for the cardinal as it has been some time since I last visited them.