myseterious clown loach death - help!

[henward]

weird, in my 2 tanks, in the past 10 days i have had m ysterious clown loach death, i find them on their side, unable to stay upright - eventually leading to death. (both tanks share same system)

water params are perfect - nitrate low, in the 10ppm mark or less. (tank suffers no temp fluctuation greater than 1 degrees c due to my drip system)

no other fish suffers from this, at first i thought my small ornates in one tank is attacking them, then my other tank started to suffer ... so far 1 large one and 1 medium on started to show symptoms.
in the other tank , 8 in the last 10 or so days have died the same exact way.

i have no clue to what it is, i introduced IAL in the tank 2 weeks ago, i have take this out and will stop to retore the usual parameters.

any ideas?

can a large ornate bite and leave no visible marks and only internal damage?
all my bichirs are going anyways, and the 2 large ornates, but just wondering what this could be.

..... a bit anxious! never really had mass death like this ever before and like i said, no other fish is affected or dying except for the clowns.

also, make it clear, there is absolutely no visible marks to indicate injury, no discolouration, fungus or wounds...
they just start to lie down

 

[henward]

Also note
that they are kinda of like confulsing and cant swim properly and what i noticed is that they cant seem to control their eye spike... tne eye spine just keep flickering in and out, sticking in and out... they cant hold it in.
weird i have NEVER seen this before.

 

[FishNCash]

Did you check for signs of ich? I just lost two nice 4.5 loaches due to ich. All I did was lower the temp by 3 degrees and that stressed up now. I increase the temp back to before and won't touch it till they are bigger.

 

[henward]

I have eliminated little things.
I have checked corners for rotting carcasses i missed, Negative.

what i have found that the IAL usually takes 4 to 6 days to start to brown the water,
These ones started to leech tannins with in 2 to 3 hours.

i checked the PH - usually my tank sits at around 7 or very high 6. Basically 7 ph, my tap water is 7.6 to 7.8 Ph.

i tested and it was beyond 6, probably a lil lower than 6.

I belive that it is PH shock, over night the PH must have dropped significantly and shocked them

Looking at the patterns of death, it started when i introduced IAL 2 weeks ago.

i have taken out all IAL and upped my water cahnges over 24 hours to restore the balance.

i feel annoyed at myself becaues the IAL was unneccesary, i wanted it really for the brown in the water - as a result, lost 2 large clowns and about 10 smaller to medium clowns in 2 weeks!!