Ich in display tank (with softies)

Raynn · Nov 30, 2025

Hi all!

On Friday, I noticed that my Moorish Idol had a few white spots that looked like ich. At first, I thought it might be stress-related, but today there are significantly more spots. He’s still eating well and behaving normally, and I haven’t seen any signs of ich on the other fish apart from Fox Face (only 2 spots which already dissapeared). About a year and a half ago, I had a major ich outbreak in this tank. Is it possible that the fish that survived that outbreak have developed a stronger resistance to the parasite?

I feed heavily and offer a wide variety of foods (frozen Mysis, chopped clams, nori, three types of pellets). Unfortunately, my Moorish Idol only eats frozen mysis and finely chopped clams - he ignores pellets, flakes, nori, etc.

I’m considering soaking his food in Metroplex. I keep only soft corals and bubble-tip anemones, and from my research, it seems that Metroplex is generally considered reef-safe when used in food, though there is still some risk to corals. Will Metroplex still be effective against ich when used this way? Are there any other methods to treat ich in a display tank? I’ve been running UV 24/7 for the past year and a half.

I’ve also noticed that my Copperband Butterfly has some unusual-looking “white stains” on its tail. I don’t personally think it’s ich, but I could be mistaken. Does anyone recognize what this might be?

Apologies for the photo quality - it’s been difficult to get a clear picture of a constantly moving fish.

Any advice would be greatly appreciated.
Thank you in advance,

Rayn

vetteguy53081 · Nov 30, 2025

Raynn said:
Hi all!

On Friday, I noticed that my Moorish Idol had a few white spots that looked like ich. At first, I thought it might be stress-related, but today there are significantly more spots. He’s still eating well and behaving normally, and I haven’t seen any signs of ich on the other fish apart from Fox Face (only 2 spots which already dissapeared). About a year and a half ago, I had a major ich outbreak in this tank. Is it possible that the fish that survived that outbreak have developed a stronger resistance to the parasite?

I feed heavily and offer a wide variety of foods (frozen Mysis, chopped clams, nori, three types of pellets). Unfortunately, my Moorish Idol only eats frozen mysis and finely chopped clams - he ignores pellets, flakes, nori, etc.

I’m considering soaking his food in Metroplex. I keep only soft corals and bubble-tip anemones, and from my research, it seems that Metroplex is generally considered reef-safe when used in food, though there is still some risk to corals. Will Metroplex still be effective against ich when used this way? Are there any other methods to treat ich in a display tank? I’ve been running UV 24/7 for the past year and a half.

I’ve also noticed that my Copperband Butterfly has some unusual-looking “white stains” on its tail. I don’t personally think it’s ich, but I could be mistaken. Does anyone recognize what this might be?

Apologies for the photo quality - it’s been difficult to get a clear picture of a constantly moving fish.

Any advice would be greatly appreciated.
Thank you in advance,

Rayn

This is unfortunate and reason many of us encourage quarantining of ALL new fish even if they were purchased as Quarantined specimens. Bow you have the inconvenience of having to remove all fish within this tank and place them in a separate housing for treatment for a Full 30 days and using copperssafe or Copper Power at 2.25 ppm monitoring the copper level with recommended Hanna Brand test kit.
Skip the Metroplex which should be used Precisely by weight and will be slow to act on what you have is now, an outbreak.
Also monitor Ammonia levels while in quarantine with a reliable test kit and add aeration during treatment using an air stone.
The display tank will have to be kept fishless (FALLOW) for 6-8 weeks to assure the existing parasites go through their life cycle without a host fish and die off and with occupants exposed, they too should go into quarantine
A quarantine tank can be as simple as a tank from a second hand store , A rubbermaid type tub or a starter kit from Walmart which most of the needed essentials.

Jay Hemdal · Nov 30, 2025

That does look like ich on the idol. The diffuse cloudiness on the CBB can also be ich, or flukes. Do you see any of the fish dart and scratch?

Oral Metroplex doesn't really work on ich. It needs to be dosed pretty high, but that makes the food bitter and the fish will stop eating it. 2% by weight would be the target, but much above 1% and the fish will start refusing the food. Also, you need to bind the medication with something like Focus or gelation.

Your fish may be past the point that this will work, but here is my article on "ich management":

"Ich Management"

Because this topic continues to come up, I wanted to create a sticky thread so that it is more easily referenced. Please understand that I am NOT presenting this as an optimum method for controlling marine ich, just putting it out there for people who want to try it. Also, do not pick and...

www.reef2reef.com

Raynn · Nov 30, 2025

I haven’t noticed any of the behaviors you mentioned. Both the Idol and the CBB are eating like pigs, swimming normally, and behaving as usual. I’ll read through your post. Thank you so much for your reply, I really appreciate it!

Raynn · Nov 30, 2025

I forgot to mention that I ordered Aquaforest Fish V and Seachem Vitality. I plan to soak the food in them - mainly frozen mysis and clams, since the CBB and Moorish Idol won’t eat anything else. Can I use both products at the same time (soaking the food in both), or would it be better to alternate - Aquaforest Fish V one day and Seachem Vitality the next? I also soak food in garlic from time to time. Should I do garlic soaking every day?

Jay Hemdal · Nov 30, 2025

Raynn said:
I forgot to mention that I ordered Aquaforest Fish V and Seachem Vitality. I plan to soak the food in them - mainly frozen mysis and clams, since the CBB and Moorish Idol won’t eat anything else. Can I use both products at the same time (soaking the food in both), or would it be better to alternate - Aquaforest Fish V one day and Seachem Vitality the next? I also soak food in garlic from time to time. Should I do garlic soaking every day?

Just to be clear - food additives don’t treat active parasitic infections. A poor diet can make a fish more prone to infections, but if the diet isn’t poor to begin with, additives won’t help. I call that the “chicken soup syndrome”.