Mystery Illness with Hillstream Loach

Good Evening Everyone,

I was working on my tank tonight and noticed my one hillstream loach looks really bad for some reason. I have two in my tank and the other looks completely fine and this guy looks like he has cotton swabs or something all over him.

He is in a 55 Gal Tank with 3 clown loaches, 3 cory cats, 2 mollies and 2 platys. I am currently testing the water now to pull all those parameters. For now, attached below are some pictures but I will say again the other hillstream loach looks perfectly fine, this guy was a little pale the last 2 weeks but what I saw tonight is new to me. The tank has been set up for about 1.5 years and I have had these two specific loaches for 6 months.

No salt in the tank, I do 20 Gallon water change every week and dose with Flourish, Potassium and Stress Coat. I use Prime as my conditioner before changing the water in the tank. The filters have Carbon, Bio Media, Sponge and Crushed Coral. I have dual filters on this a Aquaclear 70 and 55, only the 70 has crushed coral.

What are your water parameters?
Almost looks like it could be excess slime coat but that is a ton if so... And kinda looks a bit weird as well. @Colin_T or @Byron would most likely have a sure answer on it

Tank parameters are as follows:

Ammonia-0-.25ppm-This is normal in my tank, the water in my town has high ammonia and we have 3 cats.
Nitrite-0ppm
Nitrate-40-80ppm
KH-50ppm
GH-200ppm- This is throwing me off i tested it 4 times, my GH was never over 100-120ppm since I set up the tank and the only thing new I have done in the last 2-3 months is dosing with iron and I added a rock into the tank that wasnt supposed to alter anything
Ph-7.6-7.8- Its always difficult to tells this one be cause normal test is always blue and the high range is always around the same color as 7.6-7.8.

The ammonia should always be 0 and your nitrate is VERY high.
The ammonia can be solved by using a different dechlorinator like prime or API aqua essentials. The nitrate may be causing the fish to suffer. The nitrate levels are always recommended to be 20ppm or less. You have near quadruple that amount!
I would be finding ways to decrease it immediately

It use to stay below 20ppm but my one molly has given birth 7 times since March so I constantly have between 20-30 fry in there and its killing me. I just tested the GH in my 10 gal shrimp/neon tetra/ snails for my clown loaches tank and it took 29 drops to change color.....thats not even on the chart and I really hope the test kit is bad and my GH isnt that high. It is stupidly high from normal in both tanks and like I said the only changes I ahve made is liquid iron for the plants, stress coat and the rock pictured below.

Also below, I got a better picture of the hillstream loach with issues and a good one of my other hillstream who is fine. I also took pictures of the rock in each tank because i cannot remember what it is buy my LFS told me they wouldnt alter my water.

Those look like they could be mineral rocks leaching stuff into the water. Or your test kit is faulty... But that does look like a rock that could very well make water hard

Rocky998 said:

Those look like they could be mineral rocks leaching stuff into the water. Or your test kit is faulty... But that does look like a rock that could very well make water hard

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But the hillstreams are supposed to be between 100-200 ppm on GH, my KH is a little low for them but I can never get the KH past 6. I am also confused on why the one loach looks perfectly fine and the other has that "cotton swab" look to it.

Different fish may have different reactions... Have you noticed any signs of irritation from the other one like flashing?

Rocky998 said:

Different fish may have different reactions... Have you noticed any signs of irritation from the other one like flashing?

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Nope nothing and honestly the one with the cotton swab skin is acting no different from normal. he munches on an algae disk for awhile then back to skirting around the tank.

While this is of no help I never knew that a loach could have that body style. Without being stated that it is a loach I would assume it was a pleco.

IR_Crayoneater said:

Nope nothing and honestly the one with the cotton swab skin is acting no different from normal. he munches on an algae disk for awhile then back to skirting around the tank.

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Hmm... I have no idea but I still think it could be excess slime coating... I'm not 100% sure but that's what I think. Hopefully someone else can chime in who's really knows

jaylach said:

While this is of no help I never knew that a loach could have that body style. Without being stated that it is a loach I would assume it was a pleco.

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Hillstream loaches... Their really cool

jaylach said:

While this is of no help I never knew that a loach could have that body style. Without being stated that it is a loach I would assume it was a pleco.

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I love them, they are amazing to watch just basically "float" around the tank like little ghosts.

Nitrates are way off the spectrum for these fish. These need really clean water.

itiwhetu said:

Nitrates are way off the spectrum for these fish. These need really clean water.

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Ive been battling it for months because of the molly fry that are constantly in my tank from my female giving birth 7 times. Ive upped the water changes from 12.5 gallons a week to 20 gallons a week over 2 days.