Hoping I wasn’t going to have to post here, but just lost 6 of my 7 cardinal tetras today and the 7th is likely terminal and not sure on my next steps. A little bummed about the die-off as its suddenness was unexpected. As I am not sure what data is helpful, so I have included water params and significant events as it is a new tank.
Tanks is a 20 long planted tank with following water params
pH: running 7.4-7.6
Nitrates: 10-30 ppm
Hardness: 10-12dgh
Nitrite: 0
Ammonia: 0
KH/Buffer: 8-10dkh
Water Temperature: 76F
I have been running weekly checks of the above water params with a liquid kit. After I added the fish I added daily checks with Co-Op test strips and there were no elevated levels of ammonia or nitrites and the other values, excluding Nitrates, remained the same as well. Nitrate levels did vary a bit due to fertilizer additions and plant consumption. In terms of timeline and significant events I had the following:
Mid-February set up tank with hardscape, eco-complete, Fluval 30 filter tweaked with course sponge and no carbon, heater, Stingray on a timer, and a small sponge filter with air stone.
1 March added Crypt Wendetti and Parva, Java Moss, Scarlet Temple, plus Water Sprite from the Co-Op. All but the moss died back (USPS took 8 days to deliver), but everything except the Scarlet Temple had started growing well. Water params were "good" and have been using Easy Green and a little Easy Iron.
26 March added seven Cardinal Tetras from a LFS (only fish in the tank)
29 March added some additional Water Sprite to replace the Scarlet Temple which never recovered. The new Water Sprite was and is growing very well.
3 April I noticed some spots that I took to be Ich on all the Tetras (pics attached), moved them to a 5 gallon hospital tank, and used the sponge filter from the 20 long. Temp was kept at 78F.
4 April realized I had accidentally under-dosed Ich-X (0.25ml v 2.5ml) and corrected to proper dose plus started daily 30% water changes followed by re-dosing.
4 April to 6 April fish seemed to be OK, other than spots, and were eating an alternating mix of fry food and frozen Daphnia. All fish appeared energetic and water params were consistent with main tank
7 April returned home from work and 6 of 7 tetras were dead with 7th appearing unlikely to survive. Did add some Maracyn for remaining fish as dead fish seemed to have some possible fin rot that I had not noticed while they were alive.
My questions are:
Did I miss diagnose (or miss treat Ich), was it Epistylis, or something else? The rapidity of death, fatality rate, and simultaneous nature seem odd.
The following day after I had pulled the fish from the main tank I noticed some odd white growths (1-2mm and look like small white pills of cotton) on the moss and hair algae in the tank (pic attached). Curious what folk’s thoughts are on that? Other than being time coincident may be completely unrelated, but wanted to ask.
Are my water parameters just too far outside of a Tetras required range? I had hoped to get a mix of Cardinal and Rummy-nose Tetras plus some Amano shrimp for the tank, but not sure on how to proceed at this stage as I don’t know what killed the Tetras I had.
Thanks for any help or guidance,
Merrick