I have a single oscar, by himself in a 120 gallon tank, no other fish. I've kept oscars on and off for decades, never had HITH, but I've been fighting it since November. At the time, I was using RO water (the tap water here is insanely hard, about 500 ppmTDS right out of the tap), and using HOB filters.
After figuring out the filtration wasn't sufficient, I installed a fluidized bed sump (29 gallon capacity) and a surface skimmer packed with floss. I ran two courses of medicated food (Hex Shield, active ingredients being magnesium sulfate and metronidazole) for three days, to little effect.
Since then, the disease has waxed and waned: it started with small round lesions on the head, and eventually got larger lesions on the cheeks (the more characteristic "HITH" lesions), which quickly healed up and went away with no scarring. The forehead lesions remain.
A few weeks ago, I ran a two-week course of Seachem Metroplex (metronidazole as the active ingredient), and the lesions seemed to stop coming and going; after two weeks, I gave three more days' worth of Hex Shield medicated food, just as an additional measure.
Alas, it's coming back again.
The forum info asks I give all the following info: approximately three weeks of age, tank has been running for about 8-9 months now; water parameters are 0/0/60-ish, and I do 25% water changes every three days. We have ~20 ppm nitrate in the tap water, so getting those nitrates down has been difficult. Again, ONE oscar (medium-sized, under 12") in a 120 gallon tank, more like 130 gallons once hardscape and sump are figured in. Water is dechlorinated with ascorbic acid (vitamin C) as per FWS:
https://www.fs.fed.us/t-d/pubs/html/052 ... 31301.html
Temps run mid 70s to very low 80F, pH is 7.8-ish. Hardness is somewhere in the 800 ppm TDS, I'm still changing out the salt; I was adding 1 tablespoon of sea salt per 7-8 gallons up until recently. It seems to have no benefit. Again, tap water here runs 500 ppm TDS, and this disease first showed up when it was ~150 and I was using RO water.
Food has been Hikari cichlid chow, occasionally with live mealworm beetles, live bladder snails from the guppy tank, cooked frozen peas, and (most recently) red wrigglers, as per the webpage on Spironucleus. I have tried fortifying the Hikari pellets with both vitamin D and vitamin C to no apparent effect. No live fish have ever been fed.
Pic from above:
Better pic:
The lesions are deeper than they look in these pics. The white coloration comes and goes: the erosions get worse with the white, and then they lessen when the white disappears.
I'm all out of ideas. If anyone has any suggestions, I'm all ears as to what to try for this guy. Water quality went from "poor" to "excellent"- I can view the tank through 6' of water as if it were air now.
The webpage on Spironucleus says the pH tolerance of the organism that may be responsible is 5.5 to 8.5; seems that denitrifying bacteria die (or stop working) below 6 or so. And the pKa of ammonia/ammonium is around 9.26, but starts creeping up around 8.2-ish... so I suppose if it *is* caused by Spironucleus or another diplomonad, perhaps if I could keep nitrogen under control (drop the temperature a hair, increase the flow through the sump, cut way back on the food)... *maybe* that might kill the critter if I were super careful about the pH?
I'm an analytical chemist by trade, I could probably pull it off with a carefully calibrated pH meter, but I don't know how well oscars can tolerate pH 8.5.
Any thoughts on the pH thing, or anything else to try? Do the red wrigglers work "miracles", or is this poor guy doomed to have HITH forever? I've kept oscars for so many years and never dealt with this before.
After figuring out the filtration wasn't sufficient, I installed a fluidized bed sump (29 gallon capacity) and a surface skimmer packed with floss. I ran two courses of medicated food (Hex Shield, active ingredients being magnesium sulfate and metronidazole) for three days, to little effect.
Since then, the disease has waxed and waned: it started with small round lesions on the head, and eventually got larger lesions on the cheeks (the more characteristic "HITH" lesions), which quickly healed up and went away with no scarring. The forehead lesions remain.
A few weeks ago, I ran a two-week course of Seachem Metroplex (metronidazole as the active ingredient), and the lesions seemed to stop coming and going; after two weeks, I gave three more days' worth of Hex Shield medicated food, just as an additional measure.
Alas, it's coming back again.
The forum info asks I give all the following info: approximately three weeks of age, tank has been running for about 8-9 months now; water parameters are 0/0/60-ish, and I do 25% water changes every three days. We have ~20 ppm nitrate in the tap water, so getting those nitrates down has been difficult. Again, ONE oscar (medium-sized, under 12") in a 120 gallon tank, more like 130 gallons once hardscape and sump are figured in. Water is dechlorinated with ascorbic acid (vitamin C) as per FWS:
https://www.fs.fed.us/t-d/pubs/html/052 ... 31301.html
Temps run mid 70s to very low 80F, pH is 7.8-ish. Hardness is somewhere in the 800 ppm TDS, I'm still changing out the salt; I was adding 1 tablespoon of sea salt per 7-8 gallons up until recently. It seems to have no benefit. Again, tap water here runs 500 ppm TDS, and this disease first showed up when it was ~150 and I was using RO water.
Food has been Hikari cichlid chow, occasionally with live mealworm beetles, live bladder snails from the guppy tank, cooked frozen peas, and (most recently) red wrigglers, as per the webpage on Spironucleus. I have tried fortifying the Hikari pellets with both vitamin D and vitamin C to no apparent effect. No live fish have ever been fed.
Pic from above:
Better pic:
The lesions are deeper than they look in these pics. The white coloration comes and goes: the erosions get worse with the white, and then they lessen when the white disappears.
I'm all out of ideas. If anyone has any suggestions, I'm all ears as to what to try for this guy. Water quality went from "poor" to "excellent"- I can view the tank through 6' of water as if it were air now.
The webpage on Spironucleus says the pH tolerance of the organism that may be responsible is 5.5 to 8.5; seems that denitrifying bacteria die (or stop working) below 6 or so. And the pKa of ammonia/ammonium is around 9.26, but starts creeping up around 8.2-ish... so I suppose if it *is* caused by Spironucleus or another diplomonad, perhaps if I could keep nitrogen under control (drop the temperature a hair, increase the flow through the sump, cut way back on the food)... *maybe* that might kill the critter if I were super careful about the pH?
I'm an analytical chemist by trade, I could probably pull it off with a carefully calibrated pH meter, but I don't know how well oscars can tolerate pH 8.5.
Any thoughts on the pH thing, or anything else to try? Do the red wrigglers work "miracles", or is this poor guy doomed to have HITH forever? I've kept oscars for so many years and never dealt with this before.