salt question

[Alice B]

I really should look this up, but I have a few other things to do, and salt is so often recommended in freshwater aquarium keeping, that it makes a good discussion.

It seems to me that saltwater fish excrete from their kidneys differently than freshwater fish and if too much salt in the water freshwater fish waste removal doesn't work right. Somewhere I own the encyclopedia I read that in, and it was specifically an aquarium encyclopedia. How do you measure salt in a freshwater tank? Is a hydrometer sensitive enough for a saltwater tank?

Or pond? (yes I'm dealing with one where the owner dumped in a bag of water softener salt every time he added water.)

 

[Byron]

Edited to remove, I misread the original post, sorry.

 

[anewbie]

It depends a bit on species; many live bearers are comfortable or can tolerate brackish water; so for the pond you could try guppies, swordtails, mollies and similar.

 

[Alice B]

koi are who are currently in the brackish pond, but I need an accurate way to measure the salinity. At least it finally rained, that would have reduced it somewhat

 

[anewbie]

Most pet shops sell salinity test kits for salt water aquairum; would randomly presume one of those would be adequate; also i would verify what kind of salt is being dumped in the pond as it might not be sodium...

 

[jaylach]

I really should look this up, but I have a few other things to do, and salt is so often recommended in freshwater aquarium keeping, that it makes a good discussion.

It seems to me that saltwater fish excrete from their kidneys differently than freshwater fish and if too much salt in the water freshwater fish waste removal doesn't work right. Somewhere I own the encyclopedia I read that in, and it was specifically an aquarium encyclopedia. How do you measure salt in a freshwater tank? Is a hydrometer sensitive enough for a saltwater tank?

Or pond? (yes I'm dealing with one where the owner dumped in a bag of water softener salt every time he added water.)

It is a balance. You add enough salt to kill the problem but not enough to harm the fish. General rule is one heaped tablespoon per 20 liters of water.

DIRECTIONS FOR USING SALT TO TREAT FISH.

You can add rock salt (often sold as aquarium salt) or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria, fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

When you first add salt, add the salt to a small bucket of tank water and dissolve the salt. Then slowly pour the salt water into the tank near the filter outlet. Add the salt over a couple of minutes.

As to testing salinity there are higher priced digital units but something such as the following works fine.
https://www.amazon.com/dp/B0B9ZFP8FM/?tag=ff0d01-20

 

[Alice B]

The trouble with ponds and salt, is pondwater evaporates. This is a water softener salt, sodium chloride. I hope I still have a specific gravity meter around here somewhere, but if I don't , thank you for the link!

 

[anewbie]

The trouble with ponds and salt, is pondwater evaporates. This is a water softener salt, sodium chloride. I hope I still have a specific gravity meter around here somewhere, but if I don't , thank you for the link!

Yea he should stop adding the stuff... do you know why he is adding it in the first place ?

 

[Alice B]

apparently he was trying to fix his pH. However the man has died, and his widow does not know exactly why, nor do his kids. I instructed them to stop adding, I think I am going out to clean their blue barrel pond filters next week and maybe I can test salinity then

 

[jaylach]

The trouble with ponds and salt, is pondwater evaporates. This is a water softener salt, sodium chloride. I hope I still have a specific gravity meter around here somewhere, but if I don't , thank you for the link!

Too many people don't realize that water evaporates but salt does not. When one adds water to a salt environment (except for actual water changes) it should be fresh water added as the salt is still there.

Sigh, I remember helping a guy set up a large salt tank way back around 1985. The tank was pristine but he killed it by adding salt to water replacement due to evaporation. Again, water evaporates but salt does not.

Some tech does not need to change. The specific gravity tester I linked looks just the one I used in the 1980s. If it worked then it will still work now.

 

[Alice B]

I may still have one in the cupboard but I donated most of my saltwater stuff to a fish rescue organization. If not I'll order one. Deciding whether to empty and bleach my tanks. I am not sure I should be working on aquariums today, when it's hot out and I can move them all to city water in a 100 gallon tank in my greenhouse and dose for worms in there... and bleach tanks

 

[Colin_T]

Salt in marine aquariums is measured by one of 3 devices. A plastic chamber hydrometer, floating glass hydrometer, refractometer.

The plastic chamber hydrometer only measures salt levels that are close to or around seawater.

The floating glass hydrometers have a wider range but not low enough for freshwater.

A refractometer will measure any amount of salt in fresh, brackish or seawater and is what you want for measuring salt in a fish pond.

 

[jaylach]

Salt in marine aquariums is measured by one of 3 devices. A plastic chamber hydrometer, floating glass hydrometer, refractometer.

The plastic chamber hydrometer only measures salt levels that are close to or around seawater.

The floating glass hydrometers have a wider range but not low enough for freshwater.

A refractometer will measure any amount of salt in fresh, brackish or seawater and is what you want for measuring salt in a fish pond.

Thank you for the clarification. I thought salt testers all did the same thing but apparently not.

Sorry for offering a device that would likely not be effective in this situation.

 

[StevenF]

hydrometers work by measuring the density of the water. The higher the salt level the higher the water density. In salt water aquariums all tank have rouughly the same salt chemistry in the water. For rain water the density is always about the same. as well as he chemistry. For tap water the density is affected y the KH and GH levels as well as whatever is put in the water to control PH and corrosion.

I don't know enough about reflectometers to know how useful it would be.

Another device you might want to consider is a TDS pen (total dissolved solids). It is a simple electronic device that measures the conductivity of the water. It converts that the a ppm (milligram per liter) reading on the electronic display.They They are typically calibrated with salt water to about 1300ppm and will read down to 1ppm. It has enough reading range to that it might be useful. You could use it to measure the TDS or your pond or any pond without salt added and then compare that to the pond you are concerned about. If the pond has a much higher reading than the others it probably needs a water change.

 

[Alice B]

this pond may be high enough density for a regular hydrometer to work, I am not sure how many years he dumped salt in it