White Spot

[jaycat]

Hi, I am at a total loss, and would appreciate any advice you have. I have kept fish for years, but after a break of a year set up a fluval 96. Occupants-
4 hatchets
7 phantoms
5 cardinals
4 rummys
2 small cats
All that's left is 2 rummys and cats. 1 rummy looks very ill.

Hatchets went down first with spots, did water change, took out carbon, raised temp, then treated with protozin, 2 treatments, plus all necessary water changes. Increased aeration. Kept losing fish. Changed to use sera med protazol. After 24 hours fish worse, PH had crashed. Did 75% water change, left it 5 days re- treated, still losing fish. Just about to do 40% water change incase PH crashes again.
Internal filter.
PH 7.5 KH 90
Ammonia 0
Nitrite 0
Nitrate 10 ppm Temp 28-30. It's an amazon tank with only mopani wood in and plants. co2 system in.
Lfs totally stumped. Only thing I did introduce was live daphnia, was that the culprit? ANY suggestions please?

 

[scooterchick]

Sounds like there's more going on than just whitespot, it wouldn't wipe out near your entire tank, especially when you've been on the ball. The live daphnia sounds like the most likely cause.