Regarding HITH/Hexamita Disease.

[Pondscum]

Happy Thanksgiving to those who celebrate the holiday.

I've had an account here for awhile but only really lurked. I've enjoyed the threads, pictures and discussions from the active members.

I have a juvenile Oscar that I am growing out in a 60 gallon aquarium that's located in my office. I acquired the fish about a month ago and it has been doing great. The fish has easily doubled in size (length and girth) is extremely active and outgoing with a gigantic appetite. The fish is housed with three other Columbia Tetras (to large to be eaten) and a Bushy Nose Pleco. The Oscar has bright and attentive eyes, clean fins with no damage, normal gill coloration, and normal feces. The other fish have been in this aquarium for several years and are also healthy.

I feed the Oscar a variety of Hikari pellets and Omega Shrimp Sticks. I feed the fish 3X daily. I feed just what the fish can finish in a minute or so time frame. I try to remove uneaten food as quickly as possible.
I perform 2 weekly water changes of approximately 50%.

The Water Parameters are as follows:
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 10-20ppm
PH: 7.2 - 7.6

I'm using the API freshwater master testing kit. The PH may be closer to 7.6 and Nitrates may be closer to 20ppm as the color of the test results more closely resembles that range on the testing color card provided with the kit.

Tonight, I noticed what looks to be the beginning of HITH Disease on my Oscar. I've been keeping Cichlids on and off for years but this is the first time I am encountering this problem even though it seems to be quite common.

I'm looking for advice on the best course of treatment for my fish. I have Maracyn and Maracyn 2 on hand.

Anyone with direct experience treating this disease that could provide some guidance to me, would be extremely helpful as I have found conflicting information regarding treatment.

Thank you.

 

[duanes]

Oscars, and other fish from the inland, soft waters of S America, seem prone to HLLE when nitrates are high (I consider a nitrate level of 20ppm high).
And with your heavy feeding schedule (I consider 3Xs per day heavy), you will need a much more rigorous water change schedule to keep nitrate below 10ppm.
I usually do a water change if nitrate reading hits 10ppm, which usually means a 30 to 40% water change every other day for my tanks.
And that type water change schedule and volume will need to be increased, as your oscar grows.
A 60 gal tank is quite small for any cichlid that gets oscar size, because water in small volumes is easily and quickly degraded, as fish waste output increases with growth.
Using a med can be temporarily successful, but is a bandaide, because it does not solve the underlying cause, which is usually degraded water quality.

 

[Pondscum]

The 60 gallon is a growout tank, as I stated. I never considered 20ppm Nitrates high but it makes sense considering the water change schedule that I felt was aggressive. I'm going to reduce feeding and perform water changes every other day until the Nitrates are reduced. Hopefully that stops the HITH from advancing.

 

[duanes]

It is especially important to maintain a high water change schedule if your water is hard, or has high conductivity, mineral content.
When I lived in Wisconsin my water averaged about 250ppm total hardness, and I would see many scarred up oscars, and other soft water cichlids there turned into LFSs with chronic HLLE,.
It seems that the combination of nitrate with the components of hard, relatively high conductivity water is what allows for chronic diseases over time in large South American, long lived, soft water species to take hold. Cichlids like certain Geos, Uaru, and oscars, see to develop it because bacteria that that cause HLLE are ubiquitous in waters with a pH above 7, but not in the soft tannin enriched water of the Amazon basin.
Although the fish can handle the pH changes themselves, they may have not have developed immunity to the bacteria common in harder water that overwhelm their immune response..