Hi everyone, hope you guys are doing well.
I recently purchased 50 cardinal tetras from Aqua Huna, along with 2 electric blue rams. These guys all arrived Wednesday, March 16, 2022.
I temperature acclimated the fish for about 30 minutes before cutting open the bags and immediately plop-and-dropping them in, using a net and bucket to strain them out of the shipping water.
There were about 9 tetras DOA in the bags, but after being added to the tank, the remaining 41 seemed to be behaving normally and were even beginning to color up.
When I checked the tank the next morning, 3 of them were dead. Throughout the rest of the day, every 30 minutes or so, a lone cardinal tetra would begin to isolate itself from the rest of the shoal. It would then start to stick close to the surface, breathing rapidly while also losing most of its color, before eventually losing the ability to swim properly and spiraling down into the substrate.
I am now down to just 22 tetras, and another one is already starting to isolate itself.
As for the electric blue rams, they seemed to pair up within literally minutes of being added to the tank, and have been busy digging holes everywhere and doing other ram-my things, together of course. They have not shown any of the tetras' worrying behavior, although they have been occasionally chasing the healthy ones and nibbling on the dead ones.
Water parameters:
pH: ~7.4
nitrates: 5-10 ppm
hardness: ~140 ppm
nitrite: 0.5 ppm
ammonia: 0.5 ppm
KH/buffer: ~80 ppm
water temperature: 82.5 F
I am under the assumption that the presence of ammonia and nitrite are spikes due to the dead fish, and am dosing Seachem Safe directly into the aquarium, at the recommended dosage to detoxify ammonia, every 24 hours.
The tank is a 40g breeder that I am using for quarantine. It was set up about 3 weeks ago, but it uses 2 large sponge filters that have been running in another more established tank for about 4 months. The sponge filters were moved over a day before the fish arrived.
I live in Dallas, so water out of the tap is very hard. I am using a 1:1 conditioned (with Seachem Safe) tap water to RO water ratio for water changes for this particular tank. I tested the water before adding any fish, and the parameters were more or less the same minus the nitrates/nitrites/ammonia and a slightly higher pH.
What do you guys think could be the problem?
Is the water still too hard and I need to dilute the tap further?
Is everyone getting nitrite/ammonia poisoning because I am not dosing enough Seachem Safe/dosing too much Seachem Safe?
Should I have drip acclimated the cardinal tetras?
Does the tank just need to be more established to house sensitive species like cardinals for any length of time? (I am honestly surprised the rams are still alive, after everything I've heard about them being especially finicky)
Are the rams stressing the tetras to death?
I am just at a loss as to what to do right now, It's especially disheartening when the most recent reviews on Aqua Huna (the same day I got my fish, actually) are about how someone made it with 60 cardinals and no losses.
Thanks for reading.