quarantine tank high ammonia levels

Question
Hi Christy
I have inherited several normal goldfish, however one has severe fin rot so I've placed him in a quarantine tank - treating with melafix. There is a filter with polyester wool only- no carbon. However my ammonia test results are showing as very high even when I do a 50% water change. There is no problem in the healthy aquarium so its not the water. Do you know if melafix will affect the ammonia reading? Any thoughts would be appreciated.
regards Corene


Answer
Hi Corene
That all sounds good with the QT tank.  I don't use carbon in any of my tanks, it really needs to be used when removing medicines from a tank.  Over the years I've read a lot of "controversial" (I guess you could call it) debates over whether when the carbon was supposedly full, if it would leech back out all the toxins.  Some said yes, some no...So I just don't use it lol.  

Now, I'm a bit confused, you do mean the QT tank has the high ammonia right?  What are the sizes of the 2 tanks? And how big are the fish?  Now, I bet you know this already, but some of the water dechlorinators we use, like Prime and Ammo Lock, it converts the ammonia to the non toxic form(off hand I can't remember what it's called-ammonium maybe?), but that will still register as ammonia in the readings-a false positive.  Another thing, what kind of test kit are you using?  The dip stick test kits, are not very accurate.  The dropper test kits are better, but also more expensive.  

And no, I've never heard of MelaFix affecting ammonia readings.  That's such a widely used and recommended med, if it was affecting the readings, it would've been mentioned frequently on forums and such.

Hope that helps, and let me know if you have more questions!

Christy