Thread: Salt tester/meter

Anyone able to recommend one? Are the budget ones on Amazon accurate enough or should I be looking at one of the presumably, better quality units from a koi dealer?

Thanks.

Can you not just recalibrate the 'cheaper' ones using a packet of calibration powder/distilled water, maybe saving you a few quid? Don't you just mix the powder, calibrate, then rinse. I'm of the understanding that once the test fluid has been formulated it can be kept in an airtight container and reused over time, providing that the pen is rinsed in distilled water, after each use - I could be wrong though ..

Whenever I have a water sample given to me to analyse, salinity is one of the parameters included in the test and I verify the accuracy of my salinity meter with a standard salt solution which I make by dissolving common table salt in distilled water (the additives that make table salt free running make no measurable difference).

For salt dissolved in distilled water:
1 gram of salt in 1 litre makes 1 ppt (0.1%)
2 grams of salt in 1 litre makes 2 ppt (0.2%)
3 grams of salt in 1 litre makes 3 ppt (0.3%)
And so on.

In theory, if the solution is kept in a food safe bottle in a dark cool place, it will last indefinitely and you could pour out enough to calibrate a salinity meter then discard this amount afterwards (don't pour it back into the stock solution). However, since there is the possibility of bacterial contamination due to repeated exposure to air, it would be better to make a new stock solution every six months.

If you don't have distilled water, you could make the stock solution with deionised water or reverse osmosis water if you use it. However, by virtue of the way deionised or RO water are made, they aren't guaranteed to have any bacterial contamination removed. So, I would discard any stock solution made with them after three months or earlier if it looks cloudy or there is any sign of settled deposits forming at the bottom.

You could use freshly boiled and cooled tap water but many tap water supplies have trace levels of salt in them which won't be removed by boiling and may register on very accurate and sensitive salinity meters in addition to the salt deliberately added. So, if you’re not interested in absolute precision, you could use boiled tap water instead.

Just not sure which meter to purchase and was looking for recommendations.

Salt meters are easy to manufacture so no manufacturer will have a "breakthrough design" that outperforms the others so any manufacturer's product will be accurate enough for making koi baths or dips. If you test the accuracy using the standard solutions I posted above then, if there is any inaccuracy in the reading, you can make a mental adjustment each time you use it.

Originally Posted by Manky Sanke

Salt meters are easy to manufacture so no manufacturer will have a "breakthrough design" that outperforms the others so any manufacturer's product will be accurate enough for making koi baths or dips. If you test the accuracy using the standard solutions I posted above then, if there is any inaccuracy in the reading, you can make a mental adjustment each time you use it.

Thanks Syd, will refer back to that once I buy one.

Originally Posted by BrucePondsteen

I got this one recently off Amazon. Been good so far. I calibrated it using a measured dose to make 0.3%. Been treating a fish in my hospital tank, and it’s helped me keep salt at right levels.

https://www.amazon.co.uk/Salinity-Pe...ps%2C68&sr=8-4


Sent from my iPhone using Tapatalk

Thanks for that, will check it out

I've had a KoiMedic one for 20+ years, always works, just has new batteries maybe every 5 years IMO the cheapo variety is most likely to let you down right when you need it most

Originally Posted by KiOgon

I've had a KoiMedic one for 20+ years, always works, just has new batteries maybe every 5 years IMO the cheapo variety is most likely to let you down right when you need it most

Will take a look at that model John, thanks.

Attachment 43024Attachment 43025

I use one of these but it has to be the H M one as it has a small hole with an adjustment screw in it,some have the hole but no screw in it but the HM one has the screw.
Syd ( manky ) uses this type.
Can look for a link for you,think mine was about £15 posted.

https://www.waterfilterman.co.uk/wat...hoCzq4QAvD_BwE

This is where I got mine,spot on.

Originally Posted by john1

https://www.waterfilterman.co.uk/wat...hoCzq4QAvD_BwE

This is where I got mine,spot on.

Thanks John. I'm probably being a bit dim but will that measure salt?

Originally Posted by john1

Attachment 43024Attachment 43025

I use one of these but it has to be the H M one as it has a small hole with an adjustment screw in it,some have the hole but no screw in it but the HM one has the screw.
Syd ( manky ) uses this type.
Can look for a link for you,think mine was about £15 posted.

I do use that meter but for TDS not salinity. My salinity tester is a lab grade salinity tester
Dae Yoon DMT-10

digital-marine-tester.jpg

It's so old that I can't remember where I bought it or how much other than it wasn't an eye watering amount and the reason why I haven't already posted about it is because I can't see where it's currently being sold. I've searched on line and there are similar models which appear to be made by a different manufacturer using the code DMT-10 or DMT-20 but they all look different to mine.

I use it for 0.3% salt for my fry and works fine,not too good on these things myself.
All you have to do is move the decimal point on the reading.

https://www.koiforum.uk/koi-carp-cha...ght=salt+meter

Have a read of this G mac.

Sorry, John, that was a TDS meter, not a salinity meter. A TDS meter could be used to measure salinity if there was no other form of TDS in the water but, if it is used in a pond, it will measure the total of the salt plus all the other TDS that is in it apart from the salt.

Gents, thanks for taking the time to reply and advise. I’ve ended up going for the Koi Medic unit, costly but hopefully reliable.