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October 2nd, 2007, 01:32 PM
My poor guppies have developed some sort of bacterial infection (2 died) and was advised to put 1 teaspoon of melafix per 10 gal. water. Does anyone know if water changes are necessary and when? It does advise to remove carbon but no mention of how long to treat or % of water change after treatment. Thanks.

October 3rd, 2007, 10:20 AM
what kind of fish? how large of a tank? parameters and last but not least, symptoms??

im of the opinion that melafix is snake oil. do some large water changes toget it out and put your carbon back in.


October 3rd, 2007, 10:34 AM
sorry, i guess i should say this-

fin rot- 2tbs AQUARIUM salt per 5g. do daily water changes of roughly 20% and make sure you top off with fresh water before adding more salted water or your water evaporation will build up salt thats left behind.

internal bacterial infection- tetracycline FOOD fed for 10 days 2X daily

i keep both on hand at all times 'just in case' and the tetracycline food should be kept in the fridge for up to a year. January it gets replaced.

many guppies do very well with salt in their water at the above dosage(or more even) but do just ok without it if you have salt intolerant tankmates.


October 4th, 2007, 11:09 AM
Thank you Want4Rain, did as you suggested: a complete water change, put carbon back in and got as much of the Melafix disbursed as possible. Also cleaned entire aquarium, plants filters etc. with salt. This a.m. everyone is looking much healthier, will get the tetracycline food. Thanks so much.

October 4th, 2007, 12:06 PM
Thank you Want4Rain, did as you suggested: a complete water change, put carbon back in and got as much of the Melafix disbursed as possible. Also cleaned entire aquarium, plants filters etc. with salt. This a.m. everyone is looking much healthier, will get the tetracycline food. Thanks so much.

do you have a freshwater master test kit? in the fish world, cleanliness is not godliness. :) i mean for you to add aquarium salt TO the water FOR the fish to swim in. sorry, i should have specified that!!

keep a very close eye on your ammonia and nitrites. if they creep anything over .50ppm do a 50% water change.

read up here on the biological filtration in every fish tank and the vital role it plays in keeping your fish alive.

the graph shows very clearly how it establishes itself. by cleaning your tank, you probably wiped out most of your filtration system. it will need to build itself up before it can properly process the waste your fish produce. that can take a week to 6 weeks, depending on how much of the bacteria you killed by cleaning so throughly.

at this point, keep doing water changes (thats always the first course of action with each sickness... pristine water is the best treatment for most everything!!) and add in the salt to your water. if they dont clear up with that id feed the tetracycline and see if that doesnt help. usually really clean water will do it.


October 8th, 2007, 01:09 AM
Why did you think they had a bacterial infection?

Sometimes slime coat issues caused by poor water quality can appear to be infections when really they're not.
True bacterial infections don't usually clear up on their own or through water changes, though water changes are a great preventative measure and are imperative for your fishes overall health anyway.

I haven't had any luck whatsoever treating bacterial infections with Melafix, and at this point I've almost ditched it altogether. Some nasty infections such as columnaris can kill your fish within a day or 2, and trying to treat with Melafix only wastes crucial time.

The two antibacterial meds that have completely worked for me are trisulfa and erythromycin. There are several others but I've not had to try them out luckily (:fingerscr)
Unfortunately trisulfa will usually kill off 100% of your biological bacteria so it's best to ONLY use in a quarantine tank. Erythromycin isn't supposed to be as bad about it but I haven't used it in any of my main tanks so I don't know for sure.

October 31st, 2007, 11:13 AM
Hi there,
if you dumped n cleaned your whole tank, you will now need to re-cycle the tank. This will cause more stress on already possibly sick tankmates. This is a solution I would never recommend except in the most extreme cases.

There are many types of "bacterial infection". Melafix is a superb product, but it is mainly used to Prevent infections in new wounds, it is not a medicine per say and so cannot be expected to work like one. If used properly for the right kind of illnesses that Melafix is designed to treat it works very well. Melafix can be HIGHLY Toxic to fish in large quantities. It is a Must to change 30% of the water after every 4th treatment - I recommend this when treating with any medication to prevent toxicity as well as keep water as clean as possible.

For treating bacterial infections that are real bacteria (not fungal), I would recommend the use of the products Furan 2, or Maracyn 2. Tri-sulfa would not be a drug of my choice in most cases since it also destroys the live bacterial colonies in your tank and may cause a tank to go through a mini-cycle. Tetracycline is a dangerous drug, it should be used with extreme care. Keep in mind that this medicine can render fish (and humans) infertile, cause extreme birth defects, and may lead to other problems such as renal failure. It should be handled not at all by pregnant women, and with care by others. I would not use this med on any fish you ever plan to breed, present or future. I also would not use it on young fish. There are safer options.

Sometimes, a "Bacterial" infection is actually a fungus ...for most fungal infections, salt, pimafix, or furan-2 all work good. True fungus is best treated with salt baths, or salt dips.

In order to determine what illness you have, you should always post the following info for us to help you:
Tank size:
Test results for Ammonia:

This will allow us to help you choose the best med for your situation....Ammonia poisoning is one problem where the symptoms closely resemble that of a bacterial infection. Nitrite poisoning also may appear to be a disease with fish breathing heavily or gasping, flashing, and seeming sickly.
Its important to list all symptoms + test results to rule out these issues.