New Apisto dead in 4 days

[FishyMatty]

I got a couple pairs of A. Cacautoides Gold. After the first day I lost one female. But I thought she was dead when I opened the box. Then this morning I noticed that the other female was dead, and just now I noticed the largest male was dead. If anybody knows a good amount about these fish let me know if you think the water could be the issue or just the stress of being mailed across the country.
Tap ph-7.2
Tank ph 6.2 (due to co2)
kh- 30ppm
nitrates 10
nitrites/ammonia-0
gh-50-60ppm
temp 83°-84°

I have baby discus in this tank and they are happy.

[severum mama]

How did you acclimate the fish? Do you know the perams of the water where they came from? Maybe their source water was really different than yours, and they just couldn't handle the switch. Did the seller give you any sort of guarantee? How long were the fish in transit?

Sorry about your loss, that's really a bummer.

[FishyMatty]

They are being replaced for free but the guy says the only difference in water was his kh is 0 and mine is 1.5. I got some other apistos and they are all doing fine.

[Mgamer20o0]

moving is stressful for them. could have been weak from all the moving around its done.