dieing goldfish.

Question
Hi, my fancy tail goldfish have been dieing off about one/week for 4 weeks (laying at bottom of tank until death).  I have frequently changed water, checked ammonia, used Prime, etc.  My fish have shown signs of ammonia burns around gills (inflammation and redness) so I have recently treated the water with Ammolock, then tested the ammonia and it is normal.  However, I have well water and the ph of it is extremely high (at least 9).  I have put PH Down in slowly but it doesn't really seem to be helping.  What should I do now?  They have also been showing "flash" and clamped fins. Now one is swimming frantically and often on his side.  (It is a 55 gallon tank with 4 g.f. and 1 algae eater, has heater set to 68 degrees, has filter and air bubbles).  the measurements are
GH:0
kh: 240 (at least)
PH: 9
NO2:0
NO3:40

Thank you so much, my little boy has been very distressed that all his "babies" are dieing.
Jessica P.

Answer
I'm not sure what the readings are, I've never seen them put like that before.  

In any event, I would do a 50% water change and when re-adding the water be sure to use aquarium salt according to directions and a product called "Prime".  With goldfish you need to be diligent in cleaning the tank every week and a half at LEAST because they are VERY MESSY!!  Be sure to change out 25% of the water when doing it.

It could be a parasite doing it too. It's hard to tell with just what you are telling me.  Perhaps treating the tank with a broad spectrum antibiotic would be in order if the water change doesn't help.

Good luck.