To Salt or not to Salt?

[Gemma]

Without knowing much more... this might be the wisest thing to do..

Thank you for all your reply :0

 

[crsublette]

I feed my fish the way I read most experts racommend: " a few times a day, only what they eat in the first 5 minutes"

Do the experts that tell you this have a precisely designed and managed pond, with notable filtration?

 

[crsublette]

I do not have food in the skimmer box and my water shows no signs of over feeding

Fish will eat whatever is easiest for them to obtain... Scavenging for food, such as waiting for an insect or looking for a snail or sifting through algae, is more difficult than just easily consuming whatever is floating or sinking in the pond...

This is why bigger koi are even known to consume small gravel pieces... especially trash bottom feeders, like Koi and Goldfish and Tilapia, are simple constant grazers...


If you do not have a precisely designed pond, with notable filtration, that very soon captures the solid and liquid waste from the fish... and you are feeding them "a few times a day, only what they eat in the first 5 minutes"... then... from the waste the fish create will create... there will be noticeable nutrient accumulations in the water which then leads to water quality problems which then leads to potential secondary ailments (including algae)...

 

[crsublette]

I thought this was true only for fish kept in natural ponds!

Sometimes that is true...

 

[Tula]

I don't have a bottom drain, so not a truly dedicated koi pond. I feed mine once a day, especially as they've grown over the last ten years, I think they need their fish dinner

 

[crsublette]

I feed my fish the way I read most experts racommend: " a few times a day, only what they eat in the first 5 minutes"

@Gemma , generally, this is a good general rule of thumb. Anytime anyone asks about how they should go about feed fish... what you just wrote is a very good way to approach it...


...beyond that... everyone's pond is quite different... some have more biological diversity, some have more filtration (i.e., a bog, more plants, better designed pond, etc), some have much more fish, some may have a 3500 gallon liner pond that is already providing the fish with enough natural food...


My guess is during your 10 year period when there were no problems you did not follow this feeding general rule and everything was good... My guess is this might have been more food fed to the fish than you have done during your previous 10 years...

Now, fish have a tendency to reproduce like crazy, quickly overpopulating a pond, and this significantly increases competition for food... So, using fish food might be a requirement, but, then, as a result of more fish thus more feeding, this can cause problems as well... If this is true, then "thinning out the herd" might be necessary...


.... So ... without me knowing much more what is happening or what has been done...

....and you mentioning you have had all sorts of problems once you started to follow particular advice...

...the wisest thing for you to do maybe... is to ignore the advice that has been given to you... and revert back to how things were before... during a time that never gave you problems...

 

[Meyer Jordan]

@Meyer Jordan , please cite a source that indicates this is incorrect...

The confusion apparently lies in defining which type of system these established practices apply to.
As stated, they seem to indicate that these levels of salt apply to commercial aquaculture operations.
I, admittedly, have 'tunnel' thinking. I automatically think eco-pond when the subject of ponds is mentioned.
The salt levels mentioned may very well provide some prophylactic benefits in fish rearing facilities, which are mono-culture. These suggested salt levels could also be used without any adverse effect in dedicated Koi ponds, which are mono-culture also. These same salt levels, however, would, over time, wreak havoc on the zoo-plankton diversity and similarly affect any benthic organisms and possibly damage aquatic plantings that may be extant. The entire eco-system could be seriously retarded resulting ,in time, in other water quality issues.
This is why I try to determine which type of pond an inquiring poster may have before considering an answer. In many cases, the answer for eco-ponds and Koi ponds will be different.

 

[crsublette]

These same salt levels, however, would, over time, wreak havoc on the zoo-plankton diversity and similarly affect any benthic organisms and possibly damage aquatic plantings that may be extant.

Yep, this is why I also wrote...

Often times in aquaculture for food fish production, they maintain a 0.8% concentration of sodium chloride in the water since this most closely matches the salinity of fish's blood. However, they are also in a more "fish crowded" environment where fish are more likely to rub, lose mucus layers, and higher potential of bacterial infections (fin rot) due to frayed fins created by other fish. So, this gives a good benchmark where the "high end" threshold would be, but this should not be normal for our ponds.

Depending on where you live and where your source water comes from, the water salinity can range from anywhere 0.02% (that is .2ppt) to 0.18% (1.8ppt). So, many folk might not have to increase the water's salinity at all. This is the general area where salinity should be for our ponds, that is anywhere between 0.02% to 0.18%.

Then further elaborated on next post....

..but... I will stick with what I quoted... since our ponds may involve aquatic plants that could be easily damaged by a higher salinity... unless can be shown differently...

To add a bit more clarity...

Salinity concentrations allowed by municipalities in USA due to EPA secondary restrictions ("secondary" means does not require EPA enforcement) is around 500~1,000 mg/l (which is 0.5~1.0ppt or 0.05~0.10% salinity).

For groundwater, I have seen tests that would go up to 1,800 mg/l ( that is 1.8ppt or 0.18%) salinity, but the water regulators for the county would consider the groundwater safe as long as chloride and nitrite/nitrate and other primary contaminant levels were not high, controlled by EPA primary restrictions...


Anything above 0.10% salinity can damage and kill some very sensitive aquatic plants such as killing Hornwort, Anachris, Lotus, and significantly retarding Water Hyacinth and Water Lettuce.


On below, just guessing, but...

Would be quite curious to know what the salinity of Goldfish blood is... which I could never find... My guess is that their blood is much likely to be below 0.40~50% salinity...

I have come across some references saying optimum salinity tolerance of Goldfish is up to 0.30%... So possibly that might be where their blood salinity is at well...

I would not be surprised if the more fancy, fragile Goldfish like blackmoor and watkin would have a maximum tolerance of 0.10% salinity due to their blood salinity...

So... if there are these more fragile goldfish in the pond, then do not allow the salinity to go up above 0.10%.

 

[crsublette]

The confusion apparently lies in defining which type of system these established practices apply to.

Yep, I agree... from post#1, all I know is it is a pond with a waterfall... and so definitely could be just a mono-culture koi/goldfish pond or a pond that does not have many plants... but also could be a full fledged water garden pond, or as you call it a "eco-pond"...

..So I am covering all the basis...

 

[crsublette]

Lesson to be learned from all this... Best salinity for a pond is the salinity that best matches the pond's fish.

When the salinity better matches the fish, then the less energy they must use to compensate for blood salt leakage... which means... the less stressed the fish will be... ...


For reasons stated above, a 0.01% salinity water likely is more harmful to the more durable koi and goldfish whereas more appropriate for the more fragile goldfish.

 

[crsublette]

The entire eco-system could be seriously retarded resulting ,in time, in other water quality issues.

@Meyer Jordan , please cite the source for this....

...cause that is a very broad statement...


From what I Googled... benthic and plankton is a category of a huge diversity of organisms ranging from freshwater (below 0.05%) to mildly brackish (0.05% to 1%) to even seawater (3% +)... so these organisms are not something you can so easily fit in a nice box... and so sounds odd to say... "if salinity is at a low level of 0.8% or 0.30% or 0.18% or 0.02%, then this would retard all of these organisms thus creating water quality issues"...

Nitrification is not impeded by these salinity levels... cause if they were... then the RAS aquaculture industry would not do it... since the health of their livestock (along with money that is in them) depends on the nitrification process.

...but to say a salinity of 0.8% or 0.30% or 0.18% or 0.02% could lead to water quality issues... sounds suspect to me....


A salinity above 0.20% or even above 0.10% would definitely impact particular aquatic plants since pond hobbyists often try to use particular plants... but they don't have to use those plants... there are also other good plants that can be used at higher salinity....


...would be quite interesting to read a source that validates your broad statement...

 

[Gemma]

@Gemma , generally, this is a good general rule of thumb. Anytime anyone asks about how they should go about feed fish... what you just wrote is a very good way to approach it...

My guess is during your 10 year period when there were no problems you did not follow this feeding general rule and everything was good... My guess is this might have been more food fed to the fish than you have done during your previous 10 years...

I have not changed food or way of feeding the fish in a few years! The new food I was refering to in other post, was the "ken's" someone suggested, but I tried it twice and stopped using it cause my fish didn't care for it!

Before trying Omega One (a few years ago), I fed the cheapest grocery store brand,( just trowing a few pinches in the water a few times a day) and much of it ended up in the skimmer box (reason why I searched for a better food)! Now my fish really like this Omega one food, so I'm enjoying feeding them and I like to take my time, so to make it last longer, I break each stick into 2 or 3 pieces and watch them eat it all up! A few minutes later when they slow down, I stop feeding so that no food is left uneaten, and the fish are still hungry! I don't feed them again for several hours!

I've been doing this for the last few years and even though I didn't test the water, I had no diseases and no fish loss so I'm assuming it's ok to continue feeding my fish this way!

 

[Meyer Jordan]

@Meyer Jordan , please cite the source for this....

...cause that is a very broad statement...


From what I Googled... benthic and plankton is a category of a huge diversity of organisms ranging from freshwater (below 0.05%) to mildly brackish (0.05% to 1%) to even seawater (3% +)... so these organisms are not something you can so easily fit in a nice box... and so sounds odd to say... "if salinity is at a low level of 0.8% or 0.30% or 0.18% or 0.02%, then this would retard all of these organisms thus creating water quality issues"...

Nitrification is not impeded by these salinity levels... cause if they were... then the RAS aquaculture industry would not do it... since the health of their livestock (along with money that is in them) depends on the nitrification process.

...but to say a salinity of 0.8% or 0.30% or 0.18% or 0.02% could lead to water quality issues... sounds suspect to me....


A salinity above 0.20% or even above 0.10% would definitely impact particular aquatic plants since pond hobbyists often try to use particular plants... but they don't have to use those plants... there are also other good plants that can be used at higher salinity....


...would be quite interesting to read a source that validates your broad statement...

It is a broad statement because the diversity in an established eco-pond can be quite broad.
Certainly there are individual species of all aquatic organisms that are typical in different salinity ranges..fresh water, brackish and marine. Those that are classified as freshwater could certainly never adapt to marine salinity or vice versa. This is also true, but less so, of adapting of either to brackish salinity. Those that are typical in brackish salinity may or may not be able to adapt to either fresh water or marine conditions.

The point being, if individual species are able to adapt to a change in salinity then it is certainly likely that individual members of that specie are already existing in this salinity.

Without cluttering up this thread with countless links to documents and articles that can be easily accessed by anyone, it can be firmly stated that certain species of aquatic organisms micro-, meio- and macro- are quite sensitive to relatively low salinity levels and mortality will occur if salinity is raised to and above these levels. This specie mortality will cause a disruption in the biological balance of an eco-pond affecting nutrient uptake and transfer. If mortality is great enough, the DO level can be affected also. Algae will be afforded the opportunity to proliferate due to the release of nutrients back into the water column.

Will this imbalance be permanent? Probably not, but until different species are able to populate this higher salinity water the imbalance will remain.

Like many others, I completely understand the value of salt to a pond keeper. After all, it is commonly referred to as the 'Aspirin' of fish health.
What I do not understand and reject, like many others, is the use of salt as a prophylactic in any pond. Granted a lot has been written about osmoregulation but none of this literature makes a case that it is really effective over extended periods of time or is even really necessary.
It is strange that freshwater fish have lived, thrived and reproduced for eons and eons without help and I am confident that they will continue to do so.
In Aquaculture conditions, particularly RAS, salinity levels can be increased to manage the stress in the fish induced by the typical intensive crowding of these fish. Over time these fish will adapt to this increased salinity and its effects will be reduced. In Aquaculture this is not an issue as most farmed fish are brought to market size quite quickly, as little as 6 months for Tilapia which is one of the more popular farmed species in the U.S. It is important to note that salinity levels are not increased beyond the tolerance range of any particular specie. Tilapia, being a euryhaline fish can tolerate a wide range of salinity, Carp are stenohaline fish and can only tolerate a very small range of salinity.
Even though many garden ponds carry an elevated fish load, rarely are the same densities observed as those employed in intensive aquaulture. Stress induced from crowding is not a common problem in garden ponds. Given that this is the usual reason given for maintaining a certain salinity level in a pond then there IS no reason.
This then is reduced to an optional practice for pondkeepers muich like water changes. If it is not needed or does provide any detectable benefit for a pond's inhabitants, then why do it?

 

[crsublette]

Without cluttering up this thread with countless links to documents and articles that can be easily accessed by anyone, it can be firmly stated that certain species of aquatic organisms micro-, meio- and macro- are quite sensitive to relatively low salinity levels and mortality will occur if salinity is raised to and above these levels.

@Meyer Jordan , I think there is a misunderstanding here on my part...

You were talking about the quick change of salinity, such as from 0.02% to 0.30%, impacting the ecosystem, thus causing water quality problems...which I actually agree with...

....I was talking about those operators whom are using water that is already at a higher constant salinity due to their source water...

My apologies.

 

[crsublette]

It is a broad statement because the diversity in an established eco-pond can be quite broad.
Certainly there are individual species of all aquatic organisms that are typical in different salinity ranges..fresh water, brackish and marine. Those that are classified as freshwater could certainly never adapt to marine salinity or vice versa. This is also true, but less so, of adapting of either to brackish salinity. Those that are typical in brackish salinity may or may not be able to adapt to either fresh water or marine conditions.

The point being, if individual species are able to adapt to a change in salinity then it is certainly likely that individual members of that specie are already existing in this salinity.

Without cluttering up this thread with countless links to documents and articles that can be easily accessed by anyone, it can be firmly stated that certain species of aquatic organisms micro-, meio- and macro- are quite sensitive to relatively low salinity levels and mortality will occur if salinity is raised to and above these levels. This specie mortality will cause a disruption in the biological balance of an eco-pond affecting nutrient uptake and transfer. If mortality is great enough, the DO level can be affected also. Algae will be afforded the opportunity to proliferate due to the release of nutrients back into the water column.

Will this imbalance be permanent? Probably not, but until different species are able to populate this higher salinity water the imbalance will remain.

Like many others, I completely understand the value of salt to a pond keeper. After all, it is commonly referred to as the 'Aspirin' of fish health.
What I do not understand and reject, like many others, is the use of salt as a prophylactic in any pond. Granted a lot has been written about osmoregulation but none of this literature makes a case that it is really effective over extended periods of time or is even really necessary.
It is strange that freshwater fish have lived, thrived and reproduced for eons and eons without help and I am confident that they will continue to do so.
In Aquaculture conditions, particularly RAS, salinity levels can be increased to manage the stress in the fish induced by the typical intensive crowding of these fish. Over time these fish will adapt to this increased salinity and its effects will be reduced. In Aquaculture this is not an issue as most farmed fish are brought to market size quite quickly, as little as 6 months for Tilapia which is one of the more popular farmed species in the U.S. It is important to note that salinity levels are not increased beyond the tolerance range of any particular specie. Tilapia, being a euryhaline fish can tolerate a wide range of salinity, Carp are stenohaline fish and can only tolerate a very small range of salinity.
Even though many garden ponds carry an elevated fish load, rarely are the same densities observed as those employed in intensive aquaulture. Stress induced from crowding is not a common problem in garden ponds. Given that this is the usual reason given for maintaining a certain salinity level in a pond then there IS no reason.
This then is reduced to an optional practice for pondkeepers muich like water changes. If it is not needed or does provide any detectable benefit for a pond's inhabitants, then why do it?

I understand this is your supposition, which there is likely much truth to it in the general... and another good reason why people should think twice before dumping salt to increase their salinity...

My statements were not about using salt as a prophylactic in the pond...

My statements were about explaining and understanding reasonable applications of salinity and the context of "why" and "when" it is important to fish...

...and... why being concerned about salinity is likely not a problem for anyone... since I bet ya that most people's water, after dosing with salts for proper alkalinity and GH, already hovers around 0.02% salinity (if municipal) to possibly 0.18% salinity (if groundwater).