Is there truly an issue with combining prazi and copper power (or other meds)

[Spare time]

At my time at an lfs, the qt tank was hooked up to the copper system (copper power between 2-2.5ppm) but could be taken offline for medicine. In this, I have dosed api general cure and prazipro with copper still in the water, and was unable to see any detrimental effects. I have also done this with metroplex, paraguard (saved some fish with brook), and kanaplax and again, no apparent issue. The fish would either die or I could try this, so that is how this came about (I could not take out the copper). So is there really some "stressful risk" going on here, or is this just the general guideline not doing so for the sake of being unsure about what happens? The only fish that died already were very close to death, and no other fish had died in any obvious manner from the medicine mixing as far as I can tell from having done this repeatedly.

The reason I ask is that it is not uncommon for a fish to enter someone's copper QT, and then die from something copper can't treat. It would not be ideal for anyone to empty the copper to add another as then the risk for ich and velvet pops back up. So could this be a viable option for those in the QT process who have fish with some infection/parasite that is not impacted by copper?

 

[Jay Hemdal]

At my time at an lfs, the qt tank was hooked up to the copper system (copper power between 2-2.5ppm) but could be taken offline for medicine. In this, I have dosed api general cure and prazipro with copper still in the water, and was unable to see any detrimental effects. I have also done this with metroplex, paraguard (saved some fish with brook), and kanaplax and again, no apparent issue. The fish would either die or I could try this, so that is how this came about (I could not take out the copper). So is there really some "stressful risk" going on here, or is this just the general guideline not doing so for the sake of being unsure about what happens? The only fish that died already were very close to death, and no other fish had died in any obvious manner from the medicine mixing as far as I can tell from having done this repeatedly.

The reason I ask is that it is not uncommon for a fish to enter someone's copper QT, and then die from something copper can't treat. It would not be ideal for anyone to empty the copper to add another as then the risk for ich and velvet pops back up. So could this be a viable option for those in the QT process who have fish with some infection/parasite that is not impacted by copper?

My issue is that I don't have enough good data to make recommendations on mixing medications, (I use a sequential quarantine protocol) so I tend to be cautious. So many people say "copper is stressful" (I don't agree with that if it is done properly) that I'm afraid if suggest people double up on meds, and the fish die, they are going to blame my advice.
Cupramine has some weird reactions with reducing agents, including formalin. I also worry about copper power and coppersafe in that regard.

Copper and praziquantel seems to be o.k., as long as there is good aeration. Copper and antibiotics are o.k., but if the antibiotics nuke the biofilter, you'll be in for a fun ride trying to do water changes while redosing both meds. Metronidazole and Chloroquine are both antiprotozoal, so I wouldn't combine them with copper due to the overlap.

Jay