Powder Blue Tang scratching in QT - first visible symptoms today

[Jay Hemdal]

Hi @Jay Hemdal

I observed the tang for 2 hours today. He had 3 scratching episodes of 5 or fewer scratches each. It strongly resembles the onset of the previous episode (before dosing Prazi).

I cannot see anything on him yet with the naked eye and the macro photos don't reveal anything obvious to me.
Here are a few close ups from this morning:

Here is a video of him scratching followed by 1 minute of "normal" behaviour:


Based on your advice above, my thinking is that it is flukes and they were seriously set back by the Prazi but not totally eliminated, possibly because of a shorter cycle (e.g. 5 days). Also this QT had seen Prazi a few months back so it is possible a large amount of Prazi eating bacteria was ready to bloom after the first dose.

Questions:
Is the next logical step to transition him to hyposalinity?
If yes:
Do we do it right away or do we wait for the end of this 8 day Prazi treatment?
How fast can we safely drop the salinity?
Is this the same duration as the Prazi (e.g. 16 days at 16ppt) and then follow this by 21 or 30 days of copper?
Or should I aim for the lower 12ppt for 21 or 30 days and skip the copper treatment altogether?

Apologies for the barrage of questions! We're not in any rush with him so we'd rather pick the better treatment over the shortest one.

Thanks again for all your help.

It's breathing a bit fast, and some of the scratching does look like flukes, but some of it is stereotypic behavior (swimming in the same pattern). Another thing to keep in mind - if there are particles floating in the water (from the nori perhaps) if they land on the fish, it will elicit a bout of scratching. Fish do that in response to anything stuck to their skin. I didn't see a lot of particles in the water, but you would be the best judge of that.

For flukes, the treatment would be 16 ppt for 30 days (I often go 35 days). For marine ich (as well as flukes), the level needs to be 12 ppt for 30 days. However, the 12 ppt is not without some increased risk to the fish. You'll need to decide your level of risk from potential ich versus just treating for flukes.

You can lower the salinity fairly fast using dechlorinated tap water at the same temperature as the tank - lowering it in at least four steps over 48 to 72 hours.

Doh! I forgot I had posted an article on hyposalinity - here it is:

Hyposalinity

Hyposalinity Jay Hemdal 2021 This term refers to a long-term bath treatment for marine fishes in which the salt content of the water is lowered and held below the point that certain parasites can survive. The salt level reached, and the time of the treatment are the two variables...

www.reef2reef.com

Jay

 

[Julbra]

It's breathing a bit fast, and some of the scratching does look like flukes, but some of it is stereotypic behavior (swimming in the same pattern). Another thing to keep in mind - if there are particles floating in the water (from the nori perhaps) if they land on the fish, it will elicit a bout of scratching. Fish do that in response to anything stuck to their skin. I didn't see a lot of particles in the water, but you would be the best judge of that.

For flukes, the treatment would be 16 ppt for 30 days (I often go 35 days). For marine ich (as well as flukes), the level needs to be 12 ppt for 30 days. However, the 12 ppt is not without some increased risk to the fish. You'll need to decide your level of risk from potential ich versus just treating for flukes.

You can lower the salinity fairly fast using dechlorinated tap water at the same temperature as the tank - lowering it in at least four steps over 48 to 72 hours.

Doh! I forgot I had posted an article on hyposalinity - here it is:

Hyposalinity

Hyposalinity Jay Hemdal 2021 This term refers to a long-term bath treatment for marine fishes in which the salt content of the water is lowered and held below the point that certain parasites can survive. The salt level reached, and the time of the treatment are the two variables...

www.reef2reef.com

Jay

Thanks Jay.

No dirt in the water we have good filter floss in the hob.

We have decided to go directly with the 30 day 12ppt treatment. Of course if we see signs of problems we’ll be ready to raise it back to 16ppt.

Just double checking with you that there is now no point waiting on the Prazi and we can begin the transition today.

 

[Jay Hemdal]

Thanks Jay.

No dirt in the water we have good filter floss in the hob.

We have decided to go directly with the 30 day 12ppt treatment. Of course if we see signs of problems we’ll be ready to raise it back to 16ppt.

Just double checking with you that there is now no point waiting on the Prazi and we can begin the transition today.

I lost track - when did you prazi the tank last? If its been more than 5 days, you might consider redosing, waiting 24 hours, then starting the drop in salinity. If it has been less than 24 hours since you dosed the prazi, wait a full 24 hours for it to work, and then start dropping the salinity.

Jay

 

[Julbra]

I lost track - when did you prazi the tank last? If its been more than 5 days, you might consider redosing, waiting 24 hours, then starting the drop in salinity. If it has been less than 24 hours since you dosed the prazi, wait a full 24 hours for it to work, and then start dropping the salinity.

Jay

First dose on 11/2
Second dose on 11/10 (3 days ago)

So it has been less than 5 days but more than 24h.

 

[Jay Hemdal]

First dose on 11/2
Second dose on 11/10 (3 days ago)

So it has been less than 5 days but more than 24h.

O.K., I would transition into hypo now then.

Jay

 

[Julbra]

O.K., I would transition into hypo now then.

Jay

We have one more step to go to reach 12ppt later tonight.

As we crossed the 16ppt therapeutic threshold for flukes he started scratching quite vigorously especially on his head around the mouth which I had not seen him do before. It’s been 2 hours now and he is still doing it.

Not certain if it’s a good or bad thing or pure coincidence.

pH looks good so far 7.6.

 

[Jay Hemdal]

We have one more step to go to reach 12ppt later tonight.

As we crossed the 16ppt therapeutic threshold for flukes he started scratching quite vigorously especially on his head around the mouth which I had not seen him do before. It’s been 2 hours now and he is still doing it.

Not certain if it’s a good or bad thing or pure coincidence.

pH looks good so far 7.6.

The theory on that is that as the salinity lowers, the flukes get antsy and start to crawl around. That in turn causes the fish to become more irritated. Not sure if that is true or not, but I've seen that happen and I think it makes sense.

Jay

 

[Julbra]

It's been over a week since we reached full hyposalinity and today we are cautiously optimistic. Documenting my observations here.

11/15 - Reached 12ppt at 10pm, shaking and scratching constantly
11/16 - Intense scratching and twitching the whole day, looks very uncomfortable
11/17 - Scratching eases in intensity but still very frequent at 3 bouts per minute
11/18 - No change
11/19 - Scratching eases in intensity and frequency at about once per minute
11/20 - Day 5 of full hyposalinity, scratching persists about once a minute
11/21 - Colours look more intense, scratching eased a lot around once every 5 minutes
11/22 - Day 7, no scratching observed
11/23 - Today, no scratching. He attacked the pH meter with his scalpel, looking very comfortable and confident

Notes:
No further visual symptoms on the skin were observed. All seems to confirm the monogeneans diagnosis.
Salinity checked 3 times a day with well calibrated "hanna salinity tester" and maintained between 11.9ppt and 12.0ppt.
pH maintained between 7.9 and 8.0 with "Seachem marine buffer".
Appetite excellent throughout, added "Hikari Seaweed Extreme" pellets to his diet which were an (almost) instant hit.

Here he is eating nori today, looking as confident as we ever saw him


@Jay Hemdal You recommend 35 days of 16ppt hyposalinity for flukes, am I correct in assuming it is the same duration even at 12ppt?

 

[Jay Hemdal]

It's been over a week since we reached full hyposalinity and today we are cautiously optimistic. Documenting my observations here.

11/15 - Reached 12ppt at 10pm, shaking and scratching constantly
11/16 - Intense scratching and twitching the whole day, looks very uncomfortable
11/17 - Scratching eases in intensity but still very frequent at 3 bouts per minute
11/18 - No change
11/19 - Scratching eases in intensity and frequency at about once per minute
11/20 - Day 5 of full hyposalinity, scratching persists about once a minute
11/21 - Colours look more intense, scratching eased a lot around once every 5 minutes
11/22 - Day 7, no scratching observed
11/23 - Today, no scratching. He attacked the pH meter with his scalpel, looking very comfortable and confident

Notes:
No further visual symptoms on the skin were observed. All seems to confirm the monogeneans diagnosis.
Salinity checked 3 times a day with well calibrated "hanna salinity tester" and maintained between 11.9ppt and 12.0ppt.
pH maintained between 7.9 and 8.0 with "Seachem marine buffer".
Appetite excellent throughout, added "Hikari Seaweed Extreme" pellets to his diet which were an (almost) instant hit.

Here he is eating nori today, looking as confident as we ever saw him


@Jay Hemdal You recommend 35 days of 16ppt hyposalinity for flukes, am I correct in assuming it is the same duration even at 12ppt?

Great to hear that things seem to be working out! PBT can be tricky to work with...but yours looks really good.

Yes - I prefer 35 days beyond the date of the last obvious symptoms. 16 or 12 ppt should make no difference in the timeframe. However, an expert on Neobenedenia has told me that 28 days total at 16 ppt is all that is needed. I would suggest you go with my more cautious approach - unless the fish isn't stable - for example, ammonia issues in the tank, or other changes in its health (i.e. - don't blindly go with 35 days if the fish develops other issues).

Jay

 

[Julbra]

Update on day 35 of full hyposalinity at 12ppt.

Left side is immaculate:

Right side shows some white scarring where he used to scratch but the skin is smooth and healthy:

He has been scratch free since day 7 with one exception. Last week I was running a couple of days late on maintenance and he showed some scratching. Noting that the pH had dipped to 7.3. After performing a 50% water change, putting fresh fleece and carbon and bumping the pH back up the scratching stopped within a couple of hours. I am safely attributing this to dirty water and therefore not resetting the parasite clock.

As a matter of curiosity I looked but could not find any information on the effects of low pH on marine fish in hyposalinity. Can a lower pH affect the mucus coat?

He looks strong and stable so we will be following @Jay Hemdal more cautious approach with another seven days in hyposalinity for a total of 42 days (last visible symptoms at day 7 plus 35 days).

 

[Jay Hemdal]

Update on day 35 of full hyposalinity at 12ppt.

Left side is immaculate:

Right side shows some white scarring where he used to scratch but the skin is smooth and healthy:

He has been scratch free since day 7 with one exception. Last week I was running a couple of days late on maintenance and he showed some scratching. Noting that the pH had dipped to 7.3. After performing a 50% water change, putting fresh fleece and carbon and bumping the pH back up the scratching stopped within a couple of hours. I am safely attributing this to dirty water and therefore not resetting the parasite clock.

As a matter of curiosity I looked but could not find any information on the effects of low pH on marine fish in hyposalinity. Can a lower pH affect the mucus coat?

He looks strong and stable so we will be following @Jay Hemdal more cautious approach with another seven days in hyposalinity for a total of 42 days (last visible symptoms at day 7 plus 35 days).

Hyposalinity reduces the buffering ability of seawater. I’m not sure how different species react to a low pH.
Jay

 

[Weeb]

Update on day 35 of full hyposalinity at 12ppt.

Left side is immaculate:

Right side shows some white scarring where he used to scratch but the skin is smooth and healthy:

He has been scratch free since day 7 with one exception. Last week I was running a couple of days late on maintenance and he showed some scratching. Noting that the pH had dipped to 7.3. After performing a 50% water change, putting fresh fleece and carbon and bumping the pH back up the scratching stopped within a couple of hours. I am safely attributing this to dirty water and therefore not resetting the parasite clock.

As a matter of curiosity I looked but could not find any information on the effects of low pH on marine fish in hyposalinity. Can a lower pH affect the mucus coat?

He looks strong and stable so we will be following @Jay Hemdal more cautious approach with another seven days in hyposalinity for a total of 42 days (last visible symptoms at day 7 plus 35 days).

Looks like the fish has made it through this quite well. Your efforts have paid off!

 

[Julbra]

Update: we've been ramping up salinity slowly since 25th of December.

In case it's any use to anyone else I've worked out a simple formula to get consistent salinity steps up:

Where Vr is the volume to replace. Vt is total tank volume. Delta s is the salinity step desired. Sn is the new water salinity and Sc is the current tank salinity.

Another way of seeing this is:

This works with any units of volume and salinity.

For example to raise my 45L QT from 15ppt to 16ppt using new water at 35ppt:

Remove 2.25L and replace with the 35ppt water.

Same works in gallons and SG units, for example to raise a 12g tank from 1.011 to 1.012 using 1.026 new water:

Remove 0.8g and replace with the new water at 1.026.

Using this formula you can see that you will need to replace increasing amounts of water as the tank gets close to the new water salinity (the last step would in fact require a 100% change!). To combat this I mixed some brine at 49.8ppt which makes the later steps use less water.

 

[Jay Hemdal]

Update: we've been ramping up salinity slowly since 25th of December.

In case it's any use to anyone else I've worked out a simple formula to get consistent salinity steps up:

Where Vr is the volume to replace. Vt is total tank volume. Delta s is the salinity step desired. Sn is the new water salinity and Sc is the current tank salinity.

Another way of seeing this is:

This works with any units of volume and salinity.

For example to raise my 45L QT from 15ppt to 16ppt using new water at 35ppt:

Remove 2.25L and replace with the 35ppt water.

Same works in gallons and SG units, for example to raise a 12g tank from 1.011 to 1.012 using 1.026 new water:

Remove 0.8g and replace with the new water at 1.026.

Using this formula you can see that you will need to replace increasing amounts of water as the tank gets close to the new water salinity (the last step would in fact require a 100% change!). To combat this I mixed some brine at 49.8ppt which makes the later steps use less water.

Nice equations!

The "law of diminishing returns" always causes a problem for me - as you pointed out, too much seawater is used towards the end of the adjustment.

Making a strong brine is one way around this, however there is a persistent rumor in public aquariums that creating a brine solution above about 50 ppt, (and this can be in "hot spots" while mixing) that precipitates are formed, pulling some salts out of solution. This is evidenced by substantial insoluble material being formed in brine mixing tanks.

If I have a safe way to do it, I will add dry salt to a filter intake or sump to increase the salinity in the most cost effective manner possible, the math is also straightforward. The fish probably don't enjoy the pH shift or the dust of dissolving salt, but I've never seen any actual issues with them.

Jay

 

[Weeb]

Nice equations!

The "law of diminishing returns" always causes a problem for me - as you pointed out, too much seawater is used towards the end of the adjustment.

Making a strong brine is one way around this, however there is a persistent rumor in public aquariums that creating a brine solution above about 50 ppt, (and this can be in "hot spots" while mixing) that precipitates are formed, pulling some salts out of solution. This is evidenced by substantial insoluble material being formed in brine mixing tanks.

If I have a safe way to do it, I will add dry salt to a filter intake or sump to increase the salinity in the most cost effective manner possible, the math is also straightforward. The fish probably don't enjoy the pH shift or the dust of dissolving salt, but I've never seen any actual issues with them.

Jay

I like and have used myself the 'dry salt' addition. I just note that it needs to be done slowly.

 

[Julbra]

Nice equations!

The "law of diminishing returns" always causes a problem for me - as you pointed out, too much seawater is used towards the end of the adjustment.

Making a strong brine is one way around this, however there is a persistent rumor in public aquariums that creating a brine solution above about 50 ppt, (and this can be in "hot spots" while mixing) that precipitates are formed, pulling some salts out of solution. This is evidenced by substantial insoluble material being formed in brine mixing tanks.

If I have a safe way to do it, I will add dry salt to a filter intake or sump to increase the salinity in the most cost effective manner possible, the math is also straightforward. The fish probably don't enjoy the pH shift or the dust of dissolving salt, but I've never seen any actual issues with them.

Jay

Interesting. I inspected my bucket that has been mixing at 50ppt for 4 days and I indeed see small precipitation lines where the level was between steps. Nothing obvious on the pump:

I was adding salt very slowly though, going from 35ppt to 50ppt in about 6h. Like you say I can see how this would be much worse when dumping large amounts of salt quickly and creating hypersaline hotspots.

I am not too worried about the result as the precipitate at this concentration will be mostly calcium carbonates (CaCO3) so I am guessing we would just be losing a bit of calcium and alkalinity which should be fine for a fish only QT?

Maybe @Randy Holmes-Farley can weigh in as to the nature of the precipitation and composition of the resulting 50ppt brine.

 

[Jay Hemdal]

Interesting. I inspected my bucket that has been mixing at 50ppt for 4 days and I indeed see small precipitation lines where the level was between steps. Nothing obvious on the pump:

I was adding salt very slowly though, going from 35ppt to 50ppt in about 6h. Like you say I can see how this would be much worse when dumping large amounts of salt quickly and creating hypersaline hotspots.

I am not too worried about the result as the precipitate at this concentration will be mostly calcium carbonates (CaCO3) so I am guessing we would just be losing a bit of calcium and alkalinity which should be fine for a fish only QT?

Maybe @Randy Holmes-Farley can weigh in as to the nature of the precipitation and composition of the resulting 50ppt brine.

Yes - they are likely insoluble carbonates, but I can't say for certain. They are thick white "plates" that cover surfaces in large mixing vats. They break off and can be siphoned out. I've never had them tested, so I don't know their composition - we just stopped mixing strong brine and the issue also stopped.

Jay

 

[Julbra]

@Jay Hemdal we have wonderful news. Barry moved to the display this morning. We managed to transfer him without netting. He caused quite a stir in the display, especially with the female clown, but settling in nicely now. Being the only grazer he lost no time starting on the hair algae.

This fish owes you its life, we cannot thank you enough for your guidance.

 

[BetterJake]

@Jay Hemdal we have wonderful news. Barry moved to the display this morning. We managed to transfer him without netting. He caused quite a stir in the display, especially with the female clown, but settling in nicely now. Being the only grazer he lost no time starting on the hair algae.

This fish owes you its life, we cannot thank you enough for your guidance.

Amazing. Beautiful fish and great pictures!

 

[Jay Hemdal]

@Jay Hemdal we have wonderful news. Barry moved to the display this morning. We managed to transfer him without netting. He caused quite a stir in the display, especially with the female clown, but settling in nicely now. Being the only grazer he lost no time starting on the hair algae.

This fish owes you its life, we cannot thank you enough for your guidance.

Great looking fish!
Jay