Fish not doing well - Bad RODI water quality?

[spuri87]

Hello All,

A week back I did a 20% water change and noticed that the following day, my PBT showed mucus cones on its body.. I checked TDS in my RODI water and it was at 35.. I added Carbon Rox 0.8 in the tank and it appeared to make the mucus cones go away from my PBT, though my hippo tang still showed some of those.. Maybe Carbon did bind with any metals leeched in the tank and helped? not sure..

Fast forward to yesterday, I see larger number of spots on PBT and it just looked very lethargic and a little imbalanced (like a parent, you can tell when your kid isnt behaving normal, and PBT is not being its normal self today).. Nothing changed, except I added more RODI water in the ATO which I am convinced is causing some distress to the fish by adding some unwanted stuff in the tank, which in turn causes these mucus cones to appear on the fish.

While I am looking to find the root cause of the issue (ordered replacement filters for my RODI system, to test a little) and looking to upgrade the RODI system soon after I figure the root cause (plan to send water for ICP test too), I wonder if a bigger water change would help mitigate this a little.. If yes, how can I get about 30-40 gallons of water (RODI or salt water, either works for me) that I can use to replace water? Can I use distilled water from Walmart instead (just coz its easier to carry)? If you all think water change may not help at all, what are my other options?

Here is a video showing the issue I talked about in the thread:

 

[MichaelB]

Can you get very clear photos of the tangs under white lights.

That tang is highly prong to fish parasites. Hard to see it clearly with it moving in the video. Hopefully it's nothing parasite related yet it could be very early stages meaning fast action could save them. Understand that all the fish could be infected even if it's not visible. The tangs would likely be the first to show signs.

Carbon won't normay remove metals from my Understanding. Those it csn remove undersided toxins and improve water clarity.

Water changes never hurt anything so feel free to do them. Just be sure that water your adding is heated up to match tank water especially if your planning a larger water change that could greatly lower water temperature rapidly. Smaller changes on larger systems not as vital and room temp is normally fine.

Neptunes sales natural saltwater, premixed, and rodi water. Though if you just want rodi water and have some buckets or containers I would be willing to empty my 55gal barrel for you if you come by.

 

[Turkeysammich]

I don’t think that’s your problem. Fowlr systems don’t need zero tds water. The video is hard to tell what is on your fish. Pbt and blue tangs are thin skin mucus fish. Did you qt or buy from a qt place ?
I’m not a fan of carbon. I think people over do it. Less is more.

 

[Darkxerox]

Probably easier to get some dechlorinator like Prime in the meantime. Then just use the water coming out of the rodi assuming your DI isn't exhausted (check the color).

Keep feeding it well too, that algae clip looks empty. If it isn't eating well then that's a bad sign.

 

[spuri87]

Thanks @MichaelB for the offer, you are awesome.. I will give message you to talk about it in a bit!

@Turkeysammich here is a better video shared on Drobox (not sure why Youtube blurs some part of the video, but at times its better to watch the video on YT instead of embedded video on BAR) https://www.dropbox.com/scl/fi/jxz3...0714.MOV?rlkey=dlz9g2bjch0933wy5jxgfd8fh&dl=0

If its not the high TDS, I cant think of any other change that will cause this issue to re-appear within a week, only change going in the system is the RODI water through my ATO.. and 35 still seems super high, and not just TDS, maybe toxic Chloramines are also getting through if my RODI system is truly cooked! I am just thinking (writing) out loud

@Darkxerox I do have Prime at home, I will go through the instructions and add that to the tank, thanks for the tip! DI resin did look spent when I checked last week (another thread I shared on BAR), ordered replacements which should arrive tomorrow.. I feed 3 times a day, Formula 2 flakes in the morning, nori in the afternoon and TDO pellets in the evening (sometime substitute it with either frozen mysis or frozen fish eggs).. I just added NORI to the clip and PBT is at it like there is no tomorrow - thats a good sign I guess, though the spots in the dropbox video are very concerning!

 

[Kensington Reefer]

Thanks @MichaelB for the offer, you are awesome.. I will give message you to talk about it in a bit!

@Turkeysammich here is a better video shared on Drobox (not sure why Youtube blurs some part of the video, but at times its better to watch the video on YT instead of embedded video on BAR) https://www.dropbox.com/scl/fi/jxz3...0714.MOV?rlkey=dlz9g2bjch0933wy5jxgfd8fh&dl=0

If its not the high TDS, I cant think of any other change that will cause this issue to re-appear within a week, only change going in the system is the RODI water through my ATO.. and 35 still seems super high, and not just TDS, maybe toxic Chloramines are also getting through if my RODI system is truly cooked! I am just thinking (writing) out loud

@Darkxerox I do have Prime at home, I will go through the instructions and add that to the tank, thanks for the tip! DI resin did look spent when I checked last week (another thread I shared on BAR), ordered replacements which should arrive tomorrow.. I feed 3 times a day, Formula 2 flakes in the morning, nori in the afternoon and TDO pellets in the evening (sometime substitute it with either frozen mysis or frozen fish eggs).. I just added NORI to the clip and PBT is at it like there is no tomorrow - thats a good sign I guess, though the spots in the dropbox video are very concerning!

IMHO
Your fish need a better diet
I have made dietary commitments in other threads that I’m not repeating at the moment

 

[spuri87]

thanks @Kensington Reefer , I looked up your messages and I see

"Feed everything with every feeding
No single feed has all needed nutrients, but “everything” does!
A fish’s stomach is ABOUT the size of 1 of its eyeballs
“Appetizers” 4-8 times each day
Aside from frozen feeds, my tanks get pellets, flakes, nori (of different kinds), steamed broccoli
A hungry fish is an angry and weakened fish
Ample food in, water changes
Old fish…"

Do you recommend feeding more than 3 times a day? I dont feed them broccoli yet, but flakes, frozen eggs, frozen mysis (I believe its all in one, but not sure) pellets, nori (2 kinds).. will look into how I can add more variety and nutrients to their diet, but does 3 times a day seem less to you frequency wise?

 

[Kensington Reefer]

thanks @Kensington Reefer , I looked up your messages and I see

"Feed everything with every feeding
No single feed has all needed nutrients, but “everything” does!
A fish’s stomach is ABOUT the size of 1 of its eyeballs
“Appetizers” 4-8 times each day
Aside from frozen feeds, my tanks get pellets, flakes, nori (of different kinds), steamed broccoli
A hungry fish is an angry and weakened fish
Ample food in, water changes
Old fish…"

Do you recommend feeding more than 3 times a day? I dont feed them broccoli yet, but flakes, frozen eggs, frozen mysis (I believe its all in one, but not sure) pellets, nori (2 kinds).. will look into how I can add more variety and nutrients to their diet, but does 3 times a day seem less to you frequency wise?

I feed 4-7 times per day
Find the pic of all the frozen feeds

 

[Turkeysammich]

Take a close up still picture. You still didn’t answer my question. Were the fish properly qt or purchased from a store that qt’s ? The high tds is probably just a stressor not the root cause.
Btw. Those fish will eat meaty foods , nature they are vegetarian. So more algae’s

 

[Darkxerox]

Thanks @MichaelB for the offer, you are awesome.. I will give message you to talk about it in a bit!

@Turkeysammich here is a better video shared on Drobox (not sure why Youtube blurs some part of the video, but at times its better to watch the video on YT instead of embedded video on BAR) https://www.dropbox.com/scl/fi/jxz3...0714.MOV?rlkey=dlz9g2bjch0933wy5jxgfd8fh&dl=0

If its not the high TDS, I cant think of any other change that will cause this issue to re-appear within a week, only change going in the system is the RODI water through my ATO.. and 35 still seems super high, and not just TDS, maybe toxic Chloramines are also getting through if my RODI system is truly cooked! I am just thinking (writing) out loud

@Darkxerox I do have Prime at home, I will go through the instructions and add that to the tank, thanks for the tip! DI resin did look spent when I checked last week (another thread I shared on BAR), ordered replacements which should arrive tomorrow.. I feed 3 times a day, Formula 2 flakes in the morning, nori in the afternoon and TDO pellets in the evening (sometime substitute it with either frozen mysis or frozen fish eggs).. I just added NORI to the clip and PBT is at it like there is no tomorrow - thats a good sign I guess, though the spots in the dropbox video are very concerning!

Add the prime to your ATO too! I'm leaning to the chloramine stressing the acanthurus (the other fish look clean). The mucus looks chunky, not like cryptocaryon or velvet.

Edit: the trick with the clip is folding the nori as many times as you can so they can graze on it longer during the day. The good appetite is a very good sign.

 

[spuri87]

I got most of the fish (except yellows and clowns) from a tank breakdown but needed them to be fish-sit for a month at my LFS coz my tank wasnt ready.. they were in Copper for some time during that entire month, but wouldn't say they were QTed..

Yes, you are right about high TDS just being a stressor, but usually Mucus cones appear when there is a stressor in the tank, which in my case maybe this.. Ammonia is at 0, Nitrates at 15.. my Phosphates have always been high (0.45), and that again I will attribute to the bad water quality at source.. ph 7.9, temp 77 to 78.. hvnt checked alk yet.. I will add 20 ml of Prime to the tank now, and will see if that helps.. Attaching a few more pics

 

[Turkeysammich]

Humble.fish. Go ask there. Hopefully Bobby will answer your questions. Fish is thin tho. I agree with Erin. Try to fatten them up. Ick ? Maybe. Bumps look big tho. Almost looks like cotton balls but those are usually on fins only.

 

[Coral reefer]

Lots of things you can mess up with a water change that isn’t from the RODI source
Salinity, temp shock, stirring up sand bed while cleaning, etc
What are mucus cones?

 

[Turkeysammich]

I ran your photos thru grok3 and asked what it thought it was.

Is It Definitely Ich?
• Yes, highly likely if the spots are uniform white dots (not fuzzy like velvet or red like bacterial spots). Ich is the #1 cause of white-spot disease in reef tanks.
• Not ich? Could be mistaken for:
• Velvet (Amyloodinium): Golden-brown dust-like coating (harder to spot early).
• Lymphocystis: Larger, cauliflower-like growths (viral, not parasitic).
• Salt or debris: If the fish is just dirty from poor water quality.

I don’t think it’s velvet. Spots are too big.

 

[Kensington Reefer]

That tank looks new, and unstable.
Prescription:
Better feed, offered more often
Go buy NSW and do at least 30% water change every 2-3 days for the next month
Add a UV to the system

What size is that system?

 

[spuri87]

Humble.fish. Go ask there. Hopefully Bobby will answer your questions. Fish is thin tho. I agree with Erin. Try to fatten them up. Ick ? Maybe. Bumps look big tho. Almost looks like cotton balls but those are usually on fins only.

R2R folks confirmed its Mucus Cones/plugs based off size of those spots.. Besides PBT, only Hippo tang shows it in small numbers, and fish is eating well and not hiding which usually implies its not ich/velvet..

Lots of things you can mess up with a water change that isn’t from the RODI source
Salinity, temp shock, stirring up sand bed while cleaning, etc
What are mucus cones?

Thanks Coral Reefer, yeah the temp factor was tried to be taken care of, but my small heater couldnt heat my 55g barrel to 78 degrees, reduced the overall tank temp to 76, but was brought back to 78 within 30 mins.. I believe fish usually seems bigger fluctuations in reef, but God knows if thats what stressed it the 1st time.. but not sure what could have caused it now, a week later with no water changes, except maybe 5g of water from my ATO.. Salinity was maintained in replaced water and I didnt touch the sand bed at all

 

[SupraSaltyReefer]

PBT definitely has flukes. It needs a freshwater dip asap.

 

[Turkeysammich]

Asked grok3
You’re likely referring to mucous cocoons or mucus cones, which some fish, like certain species of parrotfish or wrasses, create to protect themselves while sleeping or resting. Since your original question mentioned a Powder Blue Tang (PBT) and ich, let’s clarify whether the image you referenced (from the Bareefers forum) shows a mucous cocoon or something else like ich, and address the possibility of mucus cones on a PBT.
Are Mucus Cones Present on the PBT?
• Powder Blue Tangs don’t typically produce mucus cocoons: Unlike parrotfish or some wrasses (e.g., cleaner wrasses), PBTs (Acanthurus leucosternon) do not create visible mucous cocoons or cones as a nightly protective behavior. If the image shows a PBT with a “cone” or mucus-like covering, it’s unlikely a natural cocoon.
• What you might be seeing:
• Ich (as suspected): The white spots you mentioned earlier are more likely ich (Ichthyophthirius multifiliis) cysts, not mucus cones. Ich presents as distinct, salt-grain-sized white dots scattered on the body, fins, or gills.
• Excess mucus production: PBTs, when stressed or infected (e.g., by ich, velvet, or bacterial issues), may produce excessive slime on their skin as a defense mechanism. This could appear as patchy, cloudy, or stringy mucus, potentially mistaken for a “cone.”
• Misidentification: If the fish isn’t a PBT but a species like a parrotfish, a mucous cocoon could be possible, as parrotfish are known to envelop themselves in a clear, mucus-based cocoon at night.

 

[Coral reefer]

PBT definitely has flukes. It needs a freshwater dip asap.

Not arguing at all, but how can you tell?
Let’s help others (me) learn while we are at it if we can

 

[SupraSaltyReefer]

Not arguing at all, but how can you tell?
Let’s help others (me) learn while we are at it if we can

Ich

Flukes

Ich has round dots. Like a grain of salt or sugar. Velvet is similar to ich, but much more prevalent.
Flukes are longer in shape and protrudes out more from the fish's body. See how the flukes protrudes out more a couple mm from the PBT body?