red serpaes dieing off

[sergo]

ok over the last 5 days i've had 4 serpaes die. i had 2 tonight and both were doing the same thing swimming (flopping) around in a circle all crazy and such. i immediately did a battery of water tests and here are the results which are pretty much where they stay:
ammonia 0
nitrites 0
nitrates 0
gh 6 (has slowly been rising since saturday at 4 then)
kh 7 (same as above at 4-5 then)
phos. 1-2ppm
ph 7.6-7.8 (always)
the only thing that changes is my hardness and it is a slight change over a few days. i'm really clueless as to why they keep just killing over one at a time. i thought they could tolerate my water conditions. was i wrong? they've been in there for almost 2 weeks. any ideas? thanks

[sergo]

well i decided to put my water softening pillow in my filter and do a small water change with some RO water and maybe that will help some as i think that with the increase in hardness and the ph being on their high side that maybe they are just too stressed. i hate to say this but i removed the latest one from the tank and put him in a bowl of tank water and low ph ro water just see how it affected him and to observe him better to see if i can see any signs of disease. well, he's still alive but still flipping around some (not as much as before) and is more upright for now. that's the main reason why i did the water change and put the softening pillow in, it seemed to help him. we'll see what happens and if the poor guy can pull through. it sucks to watch him suffer but i need to know if that's what is really going on in the tank before i lose them all.

[sergo]

i can't believe it, the poor fish was still alive and still swimming around erratically when i got up this morning. he doesn't show any signs of extrernal disease and it was like just all of a sudden he went retarded as he was fine when i first got home and a little while later he was going crazy. is there some sort of neurological disease that they are susceptible to that can overcome them at any time without warning? i'm lost now for sure since he made it through the night.

[Lady Hobbs]

What are your temps? I can see no other reason for this odd behavior if water is testing all at 0.

[sergo]

78 degrees