Edison, Fortunately I have never had the occasion to use this treatment but my interpretation of the dosage from the website is as follows: Days 1, 3 and 5 Carry out a 20% water change and then add Metronidazole 250mg/10gal (this being calculated from the TOTAL tank volume). Days 2 and 4 no treatment Day 6 a water change and I would think after this time no further treatment for at least another 7 days. I hope what I think is correct and wish there were other on this list who could help you. Helen > One more question, how much Metronidazole should I give on the next > treatment after changing 20% of the water, just the amount that was > replaced (20%) or should I put the full dosage of 250mg/10gal? > > Thank you very much! I hope to hear from you very soon. > > Edison ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!