Re:Suspected Fin Rot

Pete Giwojna

Dear Claire:

For this problem, the combination of the acriflavine + Furan2 should be very effective, but I don’t like using either of the medications by themselves to treat this condition. I would rather that you used the formalin bath followed by a regimen of Ampicillex, rather than using just the Furan2 by itself.

However, Furan2 is always a good medication for seahorse keepers to keep on hand, so I would go ahead and obtain the Furan2 in any case so that it’s available the next time you might need it, Claire.

How about the formalin? Were you able to obtain formalin, at least, Claire? And the methylene blue?

If you cannot obtain the acriflavine to use together with the Furan2, or the Ampicillex, as an alternative, then I would recommend that you try a long-term bath with the formalin alone. Here are the instructions for administering Chordata Formalin 3 for prolonged immersion, Claire:


(a) Since there is conflicting evidence regarding the safety of formaldehyde to biological (nitrifying) filtration, all long-term bath treatments with Formalin·3 may (at the user’s discretion) be done in a separate hospital or treatment tank.
(b) Remove granular activated carbon from all filters used on the treatment tank; clean or change the mechanical filter media (i.e., filter floss), and return the filter(s) to service (minus the carbon).
(c)Make a partial water change of approximately 25%
(d) Depending upon the condition of the fishes needing treatment (i.e., the severity of the disease, involvement of the gills and the degree of debilitation), the dosage should be varied from 1 to 2 teaspoons per 10 gallons (10 to 20 ppm.) Severely diseased or debilitated fishes should be treated at the lower dosage.
(e) The treatment may be repeated every 24 hours, by repeating all of the above steps, including the required water changes.
(f) The dosage may be increased as the condition of the fishes being treated improves.
(g) If the fishes were removed to a separate tank, the original aquarium or pond should remain devoid of all fishes for a period of at least 4 days to insure all of the remaining infestation has expired.

In that case, Claire, you should not administer a short-term formalin bath before hand. You would just transfer your male seahorse to the treatment tank and then add the formalin as described above, perform a 25% water change and then re-dosing the formalin each day (i.e., every 24 hours). The formalin alone is effective in treating fin rot and fall infections, so that would be your best option if you cannot obtain both acriflavine + Furan2, or the Ampicillex.

If you can obtain the Ampicillex, go ahead and use it in your hospital tank after administering a short (30-60 minute) formalin bath according to the instructions in my previous post.

You will know if additional formalin baths are necessary by examining the thick white line on your seahorses dorsal fin. If it is improving after the first treatment, then further short baths of formalin may not be necessary. If the white light does not look better, then don’t hesitate to repeat the short-term formalin bath every other day.

Good luck obtaining the medications you need to treat this condition and resolve the problem, Claire!

Pete Giwojna

America's Only Seahorse Aqua-Farm and One of Hawaii's Most Popular Attractions

Ocean Rider seahorse farm is a consistent Trip Advisor Certificate of Excellence Award Winner and "Top 10 Things To Do" Kona, Hawaii attraction. Our "Magical Seahorse Tours" are educational and fun for the whole family.

Tour tickets are available for Purchase On-Line. Space is limited and subject to availability.

small seahorse Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.

Seahorse Hawaii Foundation

Inspiring ocean awareness by saving the endangered seahorse and sea dragons around the world from extinction through conservation, research, propagation, and education.

Help us save the seahorse and the coral reefs they live in with a tax deductible contribution to the Seahorse Hawaii Foundation. You will be helping to protect and propagate over 25 species of endangered seahorses, sea dragons and friends.

Make A Tax-Deductible Donation Today!

A Different Kind of Farm (Video) »

Ocean Rider Kona Hawaii

Ocean Rider Kona Hawaii
Seahorse Aqua-Farm & Tours

73-4388 Ilikai Place

Kailua Kona, Hawaii 96740

Map & Directions


Contact Ocean Rider

Copyright ©1999-2023
All Rights Reserved | Ocean Rider Inc.

My Online Order Details

Purchase Policy

Site Terms and Conditions