I've recently had an outbreak of Ich and treated medication. Soon after one of my oscars hasn't been very active and recently developed a condition on one side near it's mouth . My nitrates are really high (>160ppm) which may be due to inadequate water changes. Yesterday I performed a 30% water change and plan on performing additional 30-40% every 3 days. I removed carbon from my filtration.

210 gallon Tank setup for 6 months and tank mates include 1 other Oscar, Pleco and 3 Jack Dempseys.

I believe this might be HITH or could also be caused from rocks?
Any other ideas on what this might be?

Thanks for your help.

Welcome to the community. Yes, I'm afraid that does rather look like hole in the head disease. This must have been developing for quite a while, this doesn't happen overnight. I will probably put it down to your extremely high nitrate levels, whereas high nitrate isn't really a cause for concern in small doses, extended exposure to poor water conditions can cause stress which in turn can bring on hole in the head disease.

This is quite an advanced case and it is going to take quite a while to clear up, if you have any chance of curing it, you are going to need to keep your Nitrate levels very very low, no higher than 20 ppm if possible. It may be a case that you will have to get some medication, that carry out water changes for the next couple of weeks and see if there is any improvement.

That is HITH. The most common cause of HITH is poor water quality. Can you post the results of new tests for ammonia, nitrite and nitrate.

You oscars HITH is caused be your lack of water changes. Do not put the carbon back, replace it with more bio media. Keep doing the daily water changes until your nitrates are below 40 to give your oscar good water quality

now for the cure for HITH. Im afraid the cure requires really really good water quality. Nitrates as low as possible. So you need to do large water changes (say 50%) at least 3 times a week. Be warned that HITH can take a long time to cure and you may be doing these large water changes for several weeks, maybe a few months

Good luck

Thanks for the quick replies.
I will be doing water changes/etc as suggested.
I'll post further results.

Unfortunately he didn't make it.

ugh sorry how old was he?

So sorry for your loss

Stick around and start again!

Sorry for your loss

You do need to keep your nitrates below 40 or the same could happen again

yeah that HITH looked like it had been progressing for a while. Sorry to hear that.