Combined PH & Salinity Meter

[faraday]

Want to get a handheld device to measure ph & Salinity, in a small tank to grow seaweed only.

 

Would a tds meter measure salinity accurately, as I want the salt content to be around 30 ppt?

 

The pH needs to be around 8.

 

Not looking to spend 3k baht, as I don't think my experiment warrants it.

 

Any help or advice is appreciated.

 

Thanks.

 

????

 

 

 

 

 

[Crossy]

Having failed to find a salinity meter at a sensible price I bought and calibrated a cheap TDS meter.

 

To calibrate:-

1. Measure the the TDS in your feedstock water.
2. Weigh and dissolve the correct amount (30g) of salt in a measured volume (1L) of water.
3. Measure the TDS again (this reading will be what you need to achieve).
4. Subtract 1 from 3 to get a number related to the amount of dissolved salt.

It works well enough to keep my pool chlorinator from complaining about low-salt ????

 

I'm sure your seaweed would be equally (or more) tolerant of salinity.

 

[anon2736434]

https://www.aliexpress.com/item/TDS-Digital-Salinity-Tester-Meter-for-Salt-Water-Pool-Fish-Koi-Pond-Testing/32767842531.html?spm=2114.search0104.3.1.751b7d07LleqaZ&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_204_318_319_10059_5727211_10884_10887_10696_100031_320_10084_10083_10103_10618_452_10307_532_5727311,searchweb201603_60,ppcSwitch_0&algo_expid=a513fbeb-6539-4acd-8f39-d52036777f4d-3&algo_pvid=a513fbeb-6539-4acd-8f39-d52036777f4d

Lots of choices and prices on aliexpress. I buy my PH and EC/TDS meters there for hydroponics. They also have calibration powders/solutions too.

Edited October 12, 2018 by Notagain
addition

[Isan Farang]

3 hours ago, Notagain said:

https://www.aliexpress.com/item/TDS-Digital-Salinity-Tester-Meter-for-Salt-Water-Pool-Fish-Koi-Pond-Testing/32767842531.html?spm=2114.search0104.3.1.751b7d07LleqaZ&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_204_318_319_10059_5727211_10884_10887_10696_100031_320_10084_10083_10103_10618_452_10307_532_5727311,searchweb201603_60,ppcSwitch_0&algo_expid=a513fbeb-6539-4acd-8f39-d52036777f4d-3&algo_pvid=a513fbeb-6539-4acd-8f39-d52036777f4d

Lots of choices and prices on aliexpress. I buy my PH and EC/TDS meters there for hydroponics. They also have calibration powders/solutions too.

The OP wants to measure 30 ppt, a TDS tester is of no use for this measurement. He needs a Salinity meter.

I keep salt water fish and need to measure PH, Salinity, ORP, there are lots of testing equipment on the market, but for accurate measurements you get what you pay for.

 

I use a TDS meter to confirm the condition of my RO water filter.

[anon2736434]

3 hours ago, Isan Farang said:

The OP wants to measure 30 ppt, a TDS tester is of no use for this measurement. He needs a Salinity meter.

Did you even read the description of the meter ??? What do you think a tds meter tests ? salts in the solution its testing duh. 

[faraday]

6 hours ago, Notagain said:

Did you even read the description of the meter ??? What do you think a tds meter tests ? salts in the solution its testing duh. 

It means Total Dissolved Solids, so perhaps not good enough to get a very accurate Salinity reading.

 

No need to put "duh" in your post though.

 

Anyway, I ordered a Salinity Meter, & a better 555 (more expensive) pH meter from Lazada.

 

Kerry should deliver it today. I'll post up some information on them later.

 

Enjoy your day.

[SantiSuk]

I guess we could spare a little sympathy for Notagain in that many of the sellers on eBay claim to be selling 'TDS salinity meters' or similar mangles, when they are in fact selling purely TDS meters, the readings from which need to be adjusted as Faraday implies for the (users knowledge/testing of) the TDS of the source water - and if we want to be technical some estimate of the TDS of materials added by the air and ones chemical dosing (eg cyanauric, calcium carbonate and otherpowders that have historically been placed in the pool and residues of which remain after dilution with rain or other plain water). I note that even our pool forum sponsor (if indeed they still are sponsors) list a salinity meter - out of stock for seems like a year - that looks very much like a TDS meter to me - i would offer apologies to them if I'm wrong and then I would buy one if it were stocked!

 

[Like Faraday I do not condone scornful words describing another's posting and it rebounds double fold when the critic is shown to be the one in error. Double-fold because I think Isaan Farang's comment that was essentially saying that even a TDS meter (or at least the usual pool TDS meters) doesn't measure TDS at the levels of 30ppt - which is 30,000 ppm or close to seawater, when salt-chlorinated pools typically run at 3,000 to 5,000ppm and such meters typically stop at 6,000ppm.]

 

Getting an accurate reading of salinity at a non-outrageous price is seemingly nigh impossible. I bought a set of salt test strips from the UK. They were well in date but showed that my salinity was 5,600 when a selection of (admittedly cheapo TDS meters, that I and a friend have, show TDS in my pool around the 4,500 level with underlying salinity by definition being lower than that).

 

I recall a few years back a poster was waxing lyrical about a genuine salinity test kit (ie definitely not TDS to his understanding) that worked on a count-the-number-of tabs until the test sample changes colour basis (my favourite economic but believed-to-be accurate testing style for TA and Calc testing) and was mail order from or within the USA (I can't recall whether he was specific on whether you could get the kit direct to Thailand but I do recall thinking I would order it for delivery to my sister in the UK for on-ward sending when I was next in need of salinity testing equipment. I lost the details of this chaps posting. Ring any bells with anyone?

Edited October 13, 2018 by SantiSuk

[Isan Farang]

10 hours ago, SantiSuk said:

I guess we could spare a little sympathy for Notagain in that many of the sellers on eBay claim to be selling 'TDS salinity meters' or similar mangles, when they are in fact selling purely TDS meters, the readings from which need to be adjusted as Faraday implies for the (users knowledge/testing of) the TDS of the source water - and if we want to be technical some estimate of the TDS of materials added by the air and ones chemical dosing (eg cyanauric, calcium carbonate and otherpowders that have historically been placed in the pool and residues of which remain after dilution with rain or other plain water). I note that even our pool forum sponsor (if indeed they still are sponsors) list a salinity meter - out of stock for seems like a year - that looks very much like a TDS meter to me - i would offer apologies to them if I'm wrong and then I would buy one if it were stocked!

 

[Like Faraday I do not condone scornful words describing another's posting and it rebounds double fold when the critic is shown to be the one in error. Double-fold because I think Isaan Farang's comment that was essentially saying that even a TDS meter (or at least the usual pool TDS meters) doesn't measure TDS at the levels of 30ppt - which is 30,000 ppm or close to seawater, when salt-chlorinated pools typically run at 3,000 to 5,000ppm and such meters typically stop at 6,000ppm.]

 

Getting an accurate reading of salinity at a non-outrageous price is seemingly nigh impossible. I bought a set of salt test strips from the UK. They were well in date but showed that my salinity was 5,600 when a selection of (admittedly cheapo TDS meters, that I and a friend have, show TDS in my pool around the 4,500 level with underlying salinity by definition being lower than that).

 

I recall a few years back a poster was waxing lyrical about a genuine salinity test kit (ie definitely not TDS to his understanding) that worked on a count-the-number-of tabs until the test sample changes colour basis (my favourite economic but believed-to-be accurate testing style for TA and Calc testing) and was mail order from or within the USA (I can't recall whether he was specific on whether you could get the kit direct to Thailand but I do recall thinking I would order it for delivery to my sister in the UK for on-ward sending when I was next in need of salinity testing equipment. I lost the details of this chaps posting. Ring any bells with anyone?

I my early days I tried these cheap meters and they gave all sorts of strange readings. I bit the bullet and got one recommended by a supplier in Singapore. I still have this meter after more than 10 years and it still can be calibrated with no issues.

 

If you search for American Marine (Pin Point) they have a selection of different meters and accessories.

 

 

[SantiSuk]

Many thanks Isaan Farang. I'm also at the stage where I'll pay US$100+ to get something long lasting and reliable.

 

A lot to look through! The first few I've looked at seem to be sea water monitors/testers (hence the Marine reference I guess) with the suppliers not posting to Thailand (not a fatal issue as I could stage the mailing via the UK).

 

I think the one you posted may also be testing in ppt. If so, does your one scale down or switch easily to measure swimming pool concentrations?

[Isan Farang]

32 minutes ago, SantiSuk said:

Many thanks Isaan Farang. I'm also at the stage where I'll pay US$100+ to get something long lasting and reliable.

 

A lot to look through! The first few I've looked at seem to be sea water monitors/testers (hence the Marine reference I guess) with the suppliers not posting to Thailand (not a fatal issue as I could stage the mailing via the UK).

 

I think the one you posted may also be testing in ppt. If so, does your one scale down or switch easily to measure swimming pool concentrations?

Regarding the Pin Point Meter it uses a different measurement but in the package there is a conversion chart, regarding swimming pool concentrations I have no knowledge on this subject.

 

I get my items sent to friends in either the USA or UK and get them sent by standard post to avoid the duty

 

https://americanmarineusa.com/pages/pinpoint-salinity-monitor-user-s-guide

 

http://cdn.shopify.com/s/files/1/0327/9765/files/SalinityConversion.pdf?335

 

I observed a company in BKK with a lot of related equipment but they may be to expensive

https://en.ponpe.com/

 

In the attachment is some other Pin Point meters and controller I use for my tank.

 

[SantiSuk]

Many thanks for all that info. Looks like their monitors are directed at agricutural and aquatic culture uses (which I guess is your own usage). The conversion guide doesn't look easily translatable to pool use for a non-tecchy like me and there is no calibration instruction that looks immediately apparent as being of use to a pool owner.

 

If I do investigate this line of enquiry further I think I would drop them an e-mail and ask if they do anything specifically for pool owners.

 

I really appreciate the effort you put in to giving initial info and the further and better particulars. You're a star member!