"Gray crust" on angelfish. Columnaris? Cotton wool disease? Treatment options?

[Snagrio]

I've had a group of angelfish for a little under a month. They went through quarantine just fine but within the past couple days I noticed a gray sheen on a couple of their bodies. Wasn't sure what it was but now it's developed into a full crusty growth, and I'm not sure what it is. To make matters worse they're in the main tank with catfish, snails and live plants so I have to be careful what medication I use. The most I could do right now was a 50% water change as I'm busy with work today. I desperately need advice quick before I go looking for treatments tomorrow because it's looking like any one of the possible illnesses that looks like it is highly contagious and potential community killers...

(The second image was right after the water change so excuse the bubbles).

 

[Colin_T]

Excess mucous caused by something in the water irritating the fish.

Check ammonia, nitrite, nitrate and pH.

Do a 75% water change and gravel clean the substrate every day for a week.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

If it doesn't improve after a couple of big water changes, post more pictures.

 

[Slaphppy7]

Did you cycle the tank before adding fish?

 

[Snagrio]

Excess mucous caused by something in the water irritating the fish.

Check ammonia, nitrite, nitrate and pH.

Do a 75% water change and gravel clean the substrate every day for a week.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

If it doesn't improve after a couple of big water changes, post more pictures.

I checked the water parameters, everything is 0 across the board and PH is around 7.8-8.0 (a bit high I'm aware but all the fish present haven't been bothered by it, it's just a couple of the angels). And the water is from a well, it never has any chemicals to begin with (and even then it's filtered before going through the hose).

Did you cycle the tank before adding fish?

It's been running for nearly a year and has a thriving community. The angels are very recent additions.

I do have some Ich X, Seachem Paraguard and Seachem Metroplex on hand. Would any of those be useful on top of the water changes?

EDIT: Also this is a 125 gallon live planted system with sand. I don't think changing that much water that frequently and vacuuming the substrate like that is readily feasible.

 

[Colin_T]

I do have some Ich X, Seachem Paraguard and Seachem Metroplex on hand. Would any of those be useful on top of the water changes?

There might be a contaminant in the well water that is irritating the fish.

The only other reason a fish would produce excess mucous is external protozoan parasites like Costia, Chilodonella & Trichodina. These normally cause cream, white or grey patches over parts of the body, usually the top half of the body.

The fish in the picture looks like it is completely covered in mucous, including the fins and this is normally water quality or chemicals in the water.

You can try adding salt (2 heaped tablespoons per 20 litres (5 gallons) of water). Keep the salt in the tank for 2-4 weeks. If there's no improvement after a couple of days of salt, it is not helping and you can stop using it. The salt won't affect your fish or plants.

However, you should wipe the inside of the glass down, do a big water change, gravel clean the substrate, and clean the filter before treating the tank with anything, be it salt or chemical medications. Cleaning the tank removes a lot of gunk and this means the medication can work on treating the fish instead of being wasted on the gunk.

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Metroplex won't do anything for this.

Paraguard and ich x both contain Malachite Green, which will kill external protozoan parasites. However, Malachite Green is carcinogenic (causes cancer) and is pretty toxic. If you overdose the tank you will kill the fish so work out how much water is in the tank before treating.

You also need to clean the tank before treating and increase aeration/ surface turbulence whenever using salt or medications, because they both reduce the oxygen levels in the water.

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EDIT: Also this is a 125 gallon live planted system with sand. I don't think changing that much water that frequently and vacuuming the substrate like that is readily feasible.

If you are using well water and it's free of chlorine/ chloramine, then just drain the tank down half way and refill it. It shouldn't be an issue because you don't need to dechlorinate the new water. Just drain, gravel clean and refill.

 

[Colin_T]

To work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

If you have big rocks or driftwood in the tank, remove these before measuring the height of the water level so you get a more accurate water volume.

When you measure the height, measure from the top of the substrate to the top of the water level.

You can use a permanent marker to draw a line on the tank at the water level and put down how many litres are in the tank at that level.

There is a calculator/ converter in the "FishForum.net Calculator" under "Useful Links" at the bottom of this page that will let you convert litres to gallons if you need it.

Remove carbon from the filter before treating with chemicals or it will adsorb the medication and stop it working. You do not need to remove the carbon if you use salt.

 

[Snagrio]

There might be a contaminant in the well water that is irritating the fish.

The only other reason a fish would produce excess mucous is external protozoan parasites like Costia, Chilodonella & Trichodina. These normally cause cream, white or grey patches over parts of the body, usually the top half of the body.

The fish in the picture looks like it is completely covered in mucous, including the fins and this is normally water quality or chemicals in the water.

You can try adding salt (2 heaped tablespoons per 20 litres (5 gallons) of water). Keep the salt in the tank for 2-4 weeks. If there's no improvement after a couple of days of salt, it is not helping and you can stop using it. The salt won't affect your fish or plants.

However, you should wipe the inside of the glass down, do a big water change, gravel clean the substrate, and clean the filter before treating the tank with anything, be it salt or chemical medications. Cleaning the tank removes a lot of gunk and this means the medication can work on treating the fish instead of being wasted on the gunk.

-------------------
Metroplex won't do anything for this.

Paraguard and ich x both contain Malachite Green, which will kill external protozoan parasites. However, Malachite Green is carcinogenic (causes cancer) and is pretty toxic. If you overdose the tank you will kill the fish so work out how much water is in the tank before treating.

You also need to clean the tank before treating and increase aeration/ surface turbulence whenever using salt or medications, because they both reduce the oxygen levels in the water.

-------------------

If you are using well water and it's free of chlorine/ chloramine, then just drain the tank down half way and refill it. It shouldn't be an issue because you don't need to dechlorinate the new water. Just drain, gravel clean and refill.

Considering it's only a couple angelfish that are affected and most others have been in the setup since January with no issues, I doubt it has anything to do with the source water.

I can think of one other thing. About a week, two weeks ago? I added some Controsoil to the substrate in the hopes that my plants would grow better as they haven't been looking too good as of late, and I figured a bag of that would be more cost-effective than spending a bunch on multiple bags of root tabs. Maybe that's caused issues?

 

[Colin_T]

I would have thought that the new soil would cause problems to all fish, not just the new ones.

If you have only had the angelfish for a couple of weeks, they might have an external protozoan infection, so salt or Malachite Green might help. But if it is a protozoan infection, it's a pretty serious one. Again tho, do a big water change first just in case it is something in the tank stressing the fish.

 

[Snagrio]

I have some mostly good news. The "crust" is all but gone practically overnight. The evening prior I decided to add a half dose of Seachem Paraguard (so as to try and not harm my snails) and when I looked in this morning the afflicted angels looked about as good as new with maybe the slightest remnants left but I can barely tell. There is one though that's still acting a little skittish with hiding away and didn't really eat when I offered food flakes. So I'm going to offer a more meatier selection tomorrow (blood worms/brine shrimp) and see if that perks it up.

In the meantime I did another hefty water change this evening and added what was left of the Paraguard (about another half dosage's worth). Was going to do a full cleaning of the filters but the rest of life today was more hectic than anticipated so I'll try and get to it tomorrow and go and get more Paraguard and continue with water changes for the week.