Re: Effect of medications

On Monday, 18 September 1995, HeathDA at agresearch_cri.nz wrote:

> I was planning to treat an outbreak of gill flukes in my Discus tank with 
> formaldehyde but I do not know if this is a safe medication to use in the 
> presence of plants. Could anyone tell me if formaldehyde is safe to use or 
> if it is not then recommend a treatment for gill flukes that they know is 
> safe for plants.

Are you sure you have Dactylogyrus?  Adult fish are fairly tolerant of
this organism.  Oodinium, Chilodonella, Costia, columnaris bacteria,
and a host of other pathogens can infect the gills.  Only by examining
a smear under a microscope will you know for sure.

Having said that, formalin at the levels required to kill Dactylogyrus
will trash your plants and your filter.  However, discus are very
tolerant of 1 hour dips in 200ppm formalin (1ml 37% formalin/ 10
liters water = 100ppm) in a well-aerated bare hospital tank.  This
treatment will remove most ectoparasites, but the fish may eventually
be reinfected by pathogens still in the tank.  Other treatments
include trichlorphon, which kills the flukes but not their eggs (hence
requiring retreatment at regular intervals), or Flubenol 5%
(flubendazole), an anthelmintic which will destroy both eggs and
adults (and take care of any nematodes to boot).  Fluke-Tabs, readily
available from pet stores or mail order, should be very effective as
they contain both trichlorphon and mebendazole (an anthelmintic
related to flubendazole).  I have used both Fluke-Tabs and Flubenol in
my tanks (not at the same time!) with minimal (if any) plant damage.

If you aren't sure what's bothering your fish, my recommendation would
be to try the formalin dip.  This will give them immediate relief until
you can positively identify the problem. 
Kevin Conlin   Montreal, PQ, Canada   "We're Canadians.  We HAVE to be polite"