Freshwater Dips

[Jay Hemdal]

“Freshwater dips” (FW Dips) are commonly used to dislodge certain parasites from the skin of marine fishes. This is more of a diagnostic tool, and less of a permanent cure. Dips can be used to lower the parasite load temporarily, while waiting for another treatment to begin.

Looking at the bottom of the black dip container after the fish has been returned to the tank can sometimes help identify flukes. Neobenedenia flukes are the only species large enough to be seen with the naked eye, other flukes and Turbellarian worms require the use of a microscope or strong hand lens to see them.

To perform these dips, the fish is captured and placed in a dimly lit container (black is best) of clean freshwater the same temperature as the aquarium system it came from. It is usually best not use reverse osmosis or deionized water, as there is no buffer capacity and the pH can drop too low. If you do use that water source, adjust the pH to 8.0 with baking soda. Dechlorinated tap water is suitable unless it is very acidic. The dip container should be covered with a clear material so that the fish is kept from jumping out, yet can still be observed for overt signs of stress. Hold the fish in the freshwater for five minutes (up to seven minutes for larger parasites such as copepods). If acute stress is seen, the dip may need to be terminated early. The idea is to dislodge the parasites, without unduly harming the fish. Some advocate to not aerate the water during the dip, but this is incorrect. The water motion from air bubbles can help keep the fish active so that they can be better assessed for stress. Additionally, the air bubbles help dislodge some parasites during the dip process.

Some caveats:

1) Some fish will give extreme reactions to being dipped (hepatus tangs for example), as long as they were swimming well before the dip, it is best to ignore that behavior and continue for a full five minutes.
2) Moribund (dying) fish can be dipped, but understand that the acute stress from the dip may prove fatal. The dip water should still be checked for parasites in order to possibly help any remaining fish. Moribund would include any fish that was easy to capture or a fish with a respiration rate of 200+ BPM.
3) Choose the type of net wisely, some fish have spines that will become caught in the netting. Have a pair of scissors handy to cut the net if this happens.
4) Dropping a fish while moving it to and from the dip is common, take care. Some fish have venomous spines, so know that before trying to handle any fish.
5) Fish shaking their heads violently after capture is one cause of mechanical exophthalmos (popeye), so try to gently restrain them in the net while moving them.

Aquarists are often inclined to perform a FW dip when it really isn't advisable, simply because it can be done without buying medications. However, catching fish up to perform a dip is stressful and can damage/kill the fish if not done properly - far outweighing any benefit from the dip itself.

 

[doubleshot00]

Wow very educating. I didn't know about not using rodi water.

 

[MnFish1]

“Freshwater dips” (FW Dips) are commonly used to dislodge certain parasites from the skin of marine fishes. This is more of a diagnostic tool, and less of a permanent cure. Dips can be used to lower the parasite load temporarily, while waiting for another treatment to begin.

Looking at the bottom of the black dip container after the fish has been returned to the tank can sometimes help identify flukes. Neobenedenia flukes are the only species large enough to be seen with the naked eye, other flukes and Turbellarian worms require the use of a microscope or strong hand lens to see them.

To perform these dips, the fish is captured and placed in a dimly lit container (black is best) of clean freshwater the same temperature as the aquarium system it came from. It is usually best not use reverse osmosis or deionized water, as there is no buffer capacity and the pH can drop too low. If you do use that water source, adjust the pH to 8.0 with baking soda. Dechlorinated tap water is suitable unless it is very acidic. The dip container should be covered with a clear material so that the fish is kept from jumping out, yet can still be observed for overt signs of stress. Hold the fish in the freshwater for five minutes (up to seven minutes for larger parasites such as copepods). If acute stress is seen, the dip may need to be terminated early. The idea is to dislodge the parasites, without unduly harming the fish. Some advocate to not aerate the water during the dip, but this is incorrect. The water motion from air bubbles can help keep the fish active so that they can be better assessed for stress. Additionally, the air bubbles help dislodge some parasites during the dip process.

Some caveats:

1) Some fish will give extreme reactions to being dipped (hepatus tangs for example), as long as they were swimming well before the dip, it is best to ignore that behavior and continue for a full five minutes.
2) Moribund (dying) fish can be dipped, but understand that the acute stress from the dip may prove fatal. The dip water should still be checked for parasites in order to possibly help any remaining fish. Moribund would include any fish that was easy to capture or a fish with a respiration rate of 200+ BPM.
3) Choose the type of net wisely, some fish have spines that will become caught in the netting. Have a pair of scissors handy to cut the net if this happens.
4) Dropping a fish while moving it to and from the dip is common, take care. Some fish have venomous spines, so know that before trying to handle any fish.
5) Fish shaking their heads violently after capture is one cause of mechanical exophthalmos (popeye), so try to gently restrain them in the net while moving them.

Aquarists are often inclined to perform a FW dip when it really isn't advisable, simply because it can be done without buying medications. However, catching fish up to perform a dip is stressful and can damage/kill the fish if not done properly - far outweighing any benefit from the dip itself.

Excellent summary

 

[kevgib67]

Wow very educating. I didn't know about not using rodi water.

Ya, me too. I would have assumed rodi water. Thanks Jay.

 

[EeyoreIsMySpiritAnimal]

Wow very educating. I didn't know about not using rodi water.

Me either!

 

[Jay Hemdal]

Ya, me too. I would have assumed rodi water. Thanks Jay.

You can use RODI as long as you buffer the pH to around 8.0 with bicarbonate first. Personally, I like to use tap water because I can adjust the water temp more easily before the dip.
Jay

 

[kevgib67]

You can use RODI as long as you buffer the pH to around 8.0 with bicarbonate first. Personally, I like to use tap water because I can adjust the water temp more easily before the dip.
Jay

Ya I saw the adjusting the ph with baking soda, but until now I would have just used rodi. Thanks again!

 

[MnFish1]

You can use RODI as long as you buffer the pH to around 8.0 with bicarbonate first. Personally, I like to use tap water because I can adjust the water temp more easily before the dip.
Jay

Curious - do you happen to have an approximate gm/s liter or etc - to get to that level?

 

[PotatoPig]

You can use RODI as long as you buffer the pH to around 8.0 with bicarbonate first. Personally, I like to use tap water because I can adjust the water temp more easily before the dip.
Jay

Would bottled water be OK rather than tap? I’d assume no chlorine (though would test) and comes in a handy sealed bottle that can be floated in the sump and doesn’t need treatment for chlorine.

 

[Jay Hemdal]

Would bottled water be OK rather than tap? I’d assume no chlorine (though would test) and comes in a handy sealed bottle that can be floated in the sump and doesn’t need treatment for chlorine.

Yes, as long as it isn’t distilled or “with gas”. Good idea floating it in the sump to get the temperature right.
Jay

 

[MarineandReef Jaron]

When I was at the LFS we had a local tap water of about 8.0-8.1 pH some fish like chromis or wild clowns always needed a freshwater dip and we would have hundreds of fish to do at once. We eventually decided to clear out one of the tanks in the freshwater system and run a couple dozen fish in the freshwater dip at once. This really weirded out customers to see the saltwater fish in the freshwater system but it worked well.

 

[Jay Hemdal]

When I was at the LFS we had a local tap water of about 8.0-8.1 pH some fish like chromis or wild clowns always needed a freshwater dip and we would have hundreds of fish to do at once. We eventually decided to clear out one of the tanks in the freshwater system and run a couple dozen fish in the freshwater dip at once. This really weirded out customers to see the saltwater fish in the freshwater system but it worked well.

I’ve tried mass FW dips also, but had difficulty get all the fish in and out at the same time. There is another technique that I wish I had experimented with more - giving fish a dip in 10% seawater, 90% FW. I’ve had moorish idols survive 60 minutes in that, but I don’t know if the parasites can also survive longer…..
Jay

 

[reefdummy]

“Freshwater dips” (FW Dips) are commonly used to dislodge certain parasites from the skin of marine fishes. This is more of a diagnostic tool, and less of a permanent cure. Dips can be used to lower the parasite load temporarily, while waiting for another treatment to begin.

Looking at the bottom of the black dip container after the fish has been returned to the tank can sometimes help identify flukes. Neobenedenia flukes are the only species large enough to be seen with the naked eye, other flukes and Turbellarian worms require the use of a microscope or strong hand lens to see them.

To perform these dips, the fish is captured and placed in a dimly lit container (black is best) of clean freshwater the same temperature as the aquarium system it came from. It is usually best not use reverse osmosis or deionized water, as there is no buffer capacity and the pH can drop too low. If you do use that water source, adjust the pH to 8.0 with baking soda. Dechlorinated tap water is suitable unless it is very acidic. The dip container should be covered with a clear material so that the fish is kept from jumping out, yet can still be observed for overt signs of stress. Hold the fish in the freshwater for five minutes (up to seven minutes for larger parasites such as copepods). If acute stress is seen, the dip may need to be terminated early. The idea is to dislodge the parasites, without unduly harming the fish. Some advocate to not aerate the water during the dip, but this is incorrect. The water motion from air bubbles can help keep the fish active so that they can be better assessed for stress. Additionally, the air bubbles help dislodge some parasites during the dip process.

Some caveats:

1) Some fish will give extreme reactions to being dipped (hepatus tangs for example), as long as they were swimming well before the dip, it is best to ignore that behavior and continue for a full five minutes.
2) Moribund (dying) fish can be dipped, but understand that the acute stress from the dip may prove fatal. The dip water should still be checked for parasites in order to possibly help any remaining fish. Moribund would include any fish that was easy to capture or a fish with a respiration rate of 200+ BPM.
3) Choose the type of net wisely, some fish have spines that will become caught in the netting. Have a pair of scissors handy to cut the net if this happens.
4) Dropping a fish while moving it to and from the dip is common, take care. Some fish have venomous spines, so know that before trying to handle any fish.
5) Fish shaking their heads violently after capture is one cause of mechanical exophthalmos (popeye), so try to gently restrain them in the net while moving them.

Aquarists are often inclined to perform a FW dip when it really isn't advisable, simply because it can be done without buying medications. However, catching fish up to perform a dip is stressful and can damage/kill the fish if not done properly - far outweighing any benefit from the dip itself.

Can you ID uronema that way it it would be only the scraping the fish?

 

[leftovervirus]

“Freshwater dips” (FW Dips) are commonly used to dislodge certain parasites from the skin of marine fishes. This is more of a diagnostic tool, and less of a permanent cure. Dips can be used to lower the parasite load temporarily, while waiting for another treatment to begin.

Looking at the bottom of the black dip container after the fish has been returned to the tank can sometimes help identify flukes. Neobenedenia flukes are the only species large enough to be seen with the naked eye, other flukes and Turbellarian worms require the use of a microscope or strong hand lens to see them.

To perform these dips, the fish is captured and placed in a dimly lit container (black is best) of clean freshwater the same temperature as the aquarium system it came from. It is usually best not use reverse osmosis or deionized water, as there is no buffer capacity and the pH can drop too low. If you do use that water source, adjust the pH to 8.0 with baking soda. Dechlorinated tap water is suitable unless it is very acidic. The dip container should be covered with a clear material so that the fish is kept from jumping out, yet can still be observed for overt signs of stress. Hold the fish in the freshwater for five minutes (up to seven minutes for larger parasites such as copepods). If acute stress is seen, the dip may need to be terminated early. The idea is to dislodge the parasites, without unduly harming the fish. Some advocate to not aerate the water during the dip, but this is incorrect. The water motion from air bubbles can help keep the fish active so that they can be better assessed for stress. Additionally, the air bubbles help dislodge some parasites during the dip process.

Some caveats:

1) Some fish will give extreme reactions to being dipped (hepatus tangs for example), as long as they were swimming well before the dip, it is best to ignore that behavior and continue for a full five minutes.
2) Moribund (dying) fish can be dipped, but understand that the acute stress from the dip may prove fatal. The dip water should still be checked for parasites in order to possibly help any remaining fish. Moribund would include any fish that was easy to capture or a fish with a respiration rate of 200+ BPM.
3) Choose the type of net wisely, some fish have spines that will become caught in the netting. Have a pair of scissors handy to cut the net if this happens.
4) Dropping a fish while moving it to and from the dip is common, take care. Some fish have venomous spines, so know that before trying to handle any fish.
5) Fish shaking their heads violently after capture is one cause of mechanical exophthalmos (popeye), so try to gently restrain them in the net while moving them.

Aquarists are often inclined to perform a FW dip when it really isn't advisable, simply because it can be done without buying medications. However, catching fish up to perform a dip is stressful and can damage/kill the fish if not done properly - far outweighing any benefit from the dip itself.

I've used RODI water to much success on various species from Tangs to Ocellaris. just as long as the temp is the same as the host tank.

 

[leftovervirus]

“Freshwater dips” (FW Dips) are commonly used to dislodge certain parasites from the skin of marine fishes. This is more of a diagnostic tool, and less of a permanent cure. Dips can be used to lower the parasite load temporarily, while waiting for another treatment to begin.

Looking at the bottom of the black dip container after the fish has been returned to the tank can sometimes help identify flukes. Neobenedenia flukes are the only species large enough to be seen with the naked eye, other flukes and Turbellarian worms require the use of a microscope or strong hand lens to see them.

To perform these dips, the fish is captured and placed in a dimly lit container (black is best) of clean freshwater the same temperature as the aquarium system it came from. It is usually best not use reverse osmosis or deionized water, as there is no buffer capacity and the pH can drop too low. If you do use that water source, adjust the pH to 8.0 with baking soda. Dechlorinated tap water is suitable unless it is very acidic. The dip container should be covered with a clear material so that the fish is kept from jumping out, yet can still be observed for overt signs of stress. Hold the fish in the freshwater for five minutes (up to seven minutes for larger parasites such as copepods). If acute stress is seen, the dip may need to be terminated early. The idea is to dislodge the parasites, without unduly harming the fish. Some advocate to not aerate the water during the dip, but this is incorrect. The water motion from air bubbles can help keep the fish active so that they can be better assessed for stress. Additionally, the air bubbles help dislodge some parasites during the dip process.

Some caveats:

1) Some fish will give extreme reactions to being dipped (hepatus tangs for example), as long as they were swimming well before the dip, it is best to ignore that behavior and continue for a full five minutes.
2) Moribund (dying) fish can be dipped, but understand that the acute stress from the dip may prove fatal. The dip water should still be checked for parasites in order to possibly help any remaining fish. Moribund would include any fish that was easy to capture or a fish with a respiration rate of 200+ BPM.
3) Choose the type of net wisely, some fish have spines that will become caught in the netting. Have a pair of scissors handy to cut the net if this happens.
4) Dropping a fish while moving it to and from the dip is common, take care. Some fish have venomous spines, so know that before trying to handle any fish.
5) Fish shaking their heads violently after capture is one cause of mechanical exophthalmos (popeye), so try to gently restrain them in the net while moving them.

Aquarists are often inclined to perform a FW dip when it really isn't advisable, simply because it can be done without buying medications. However, catching fish up to perform a dip is stressful and can damage/kill the fish if not done properly - far outweighing any benefit from the dip itself.

I've used RODI water to great success on numerous dips I've had to do. From tangs to ocellaris, as long as the temp is ok i've seen more success with RODI vs tap. no buffering of PH on either.

 

[C4ctus99]

Just out of curiosity, what are the effects of the sudden and dramatic changes in salinity? Going from proper salt to zero salt and then back up to the SP of your tank? I am new to the hobby and didn’t realize this was a thing

 

[Jay Hemdal]

Just out of curiosity, what are the effects of the sudden and dramatic changes in salinity? Going from proper salt to zero salt and then back up to the SP of your tank? I am new to the hobby and didn’t realize this was a thing

Healthy fish can handle that abrupt of a change for 5 to 7 minutes, but many external parasites cannot, thus the dip serves as a diagnostic tool and to buy some time until a full treatment can be started.
Jay

 

[KyleC]

Great post and info guys! Currently waiting on some coppersafe to arrive, in the meantime I want to try and give my porcupine puffer some relief from ich using a FW dip.

So to be clear, I can use tapwater? Providing it is the same temp as my DT, well aerated, and try match pH using baking soda? Or does pH not matter? Then place him in for around 5 minutes?

LFS recommended using eSHa Oodinex in the DT as it's reef safe, however despite cautiously undosing to be safe, my corals appeared to suffer. So stopped treatment on day 2 and hoping FW dip will help until coppersafe arrives.

I don't want to net him incase he inflates, so plan on using small container which means some DT water will mix with FW, but that should be ok?

 

[Jay Hemdal]

Great post and info guys! Currently waiting on some coppersafe to arrive, in the meantime I want to try and give my porcupine puffer some relief from ich using a FW dip.

So to be clear, I can use tapwater? Providing it is the same temp as my DT, well aerated, and try match pH using baking soda? Or does pH not matter? Then place him in for around 5 minutes?

LFS recommended using eSHa Oodinex in the DT as it's reef safe, however despite cautiously undosing to be safe, my corals appeared to suffer. So stopped treatment on day 2 and hoping FW dip will help until coppersafe arrives.

I don't know the pH of tap water in Ireland, but here in the US, most tap water has a pH above 7.5, so if fine to use as-is (better than RODI water). You need to match temperatures and most people dechlorinate (but I often don't). Then, hold the fish in the FW for 5 minutes with aeration (not that the fish needs it, just to keep the fish moving a bit so you can better assess its condition).

FW dips really have minimal effect on ich trophonts though - they are mostly useful for dislodging flukes.

Jay

 

[KyleC]

Ah ok, so there's a chance then this could do more harm than good with the stress. I wouldn't want him suffering if it's not going to provide him adequate relief temporarily.

Thanks Jay, I really appreciate your responsiveness on this forum and valuable advice! You've helped me a lot already allowing me to relax and stay positive.