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TDS PEN

I use test kits, but these are the only things I test for, GH and KH. Only because I view calcium and carbonates as part of my ferts. I think it helps my vals.
 
Just done a 50% water change and also added loads more plants at the same time. So I disturbed the soil. TDS reading before water change was 178ppm. TDS reading after water change 164ppm not a big difference. Could this be because of the soil been disturbed due to planting new plants?
 
Just done a 50% water change and also added loads more plants at the same time. So I disturbed the soil. TDS reading before water change was 178ppm. TDS reading after water change 164ppm not a big difference. Could this be because of the soil been disturbed due to planting new plants?
Could be anything. Whilst it is likely that they are basically the same it is possible that the water is now completely different...

One way of looking at is thinking that TDS is the number of fruit pieces in your tank. You put 178 bits of orange in there and your measurement is 178. If you now have a reading of 164 this could mean you have removed 14 pieces of orange but it could also mean you have removed all 178 pieces of orange and added 164 pieces of apple. It is just the total and on its own it isn't much use.

I used the calibration solution to validate my assumption that the cheapy meter I got was as useful as a random number generator.

I think shrimp keepers are obsessed with TDS based on keeping them in RO water and adding back minerals. In doing this TDS does become useful as you can use it to reconstitute to the desired values (you are adding the only things to the water so the total measurement is showing what you have added).

I use my TDS pen as a guide of how much RO to cut my tap water with. My tap water is consistently about 320 TDS but more importantly GH 12. I want my GH to be 8 so I mix till it is about 220. I also use it as an indication of any changes. If my tap water suddenly became 100 or 500 I would start looking into it before doing water changes.
 
Could be anything. Whilst it is likely that they are basically the same it is possible that the water is now completely different...

One way of looking at is thinking that TDS is the number of fruit pieces in your tank. You put 178 bits of orange in there and your measurement is 178. If you now have a reading of 164 this could mean you have removed 14 pieces of orange but it could also mean you have removed all 178 pieces of orange and added 164 pieces of apple. It is just the total and on its own it isn't much use.

I used the calibration solution to validate my assumption that the cheapy meter I got was as useful as a random number generator.

I think shrimp keepers are obsessed with TDS based on keeping them in RO water and adding back minerals. In doing this TDS does become useful as you can use it to reconstitute to the desired values (you are adding the only things to the water so the total measurement is showing what you have added).

I use my TDS pen as a guide of how much RO to cut my tap water with. My tap water is consistently about 320 TDS but more importantly GH 12. I want my GH to be 8 so I mix till it is about 220. I also use it as an indication of any changes. If my tap water suddenly became 100 or 500 I would start looking into it before doing water changes.
The only reason I got this TDS PEN was because I was loosing shrimp so just wanted to see if my TDS was high enough from the tap/My tank water. Are TDS and GH 2 totally different parameters. Reason I ask because do I need both to be a high number to keep my cherry shrimp.
Thanks lee
 
used the calibration solution to validate my assumption that the cheapy meter I got was as useful as a random number generator.

So you only used solution to test your cheap meter? And not because you needed to use it?
 
Could be anything. Whilst it is likely that they are basically the same it is possible that the water is now completely different...

One way of looking at is thinking that TDS is the number of fruit pieces in your tank. You put 178 bits of orange in there and your measurement is 178. If you now have a reading of 164 this could mean you have removed 14 pieces of orange but it could also mean you have removed all 178 pieces of orange and added 164 pieces of apple. It is just the total and on its own it isn't much use.

I used the calibration solution to validate my assumption that the cheapy meter I got was as useful as a random number generator.

I think shrimp keepers are obsessed with TDS based on keeping them in RO water and adding back minerals. In doing this TDS does become useful as you can use it to reconstitute to the desired values (you are adding the only things to the water so the total measurement is showing what you have added).

I use my TDS pen as a guide of how much RO to cut my tap water with. My tap water is consistently about 320 TDS but more importantly GH 12. I want my GH to be 8 so I mix till it is about 220. I also use it as an indication of any changes. If my tap water suddenly became 100 or 500 I would start looking into it before doing water changes.
So basically the lower the TDS the lower the GH is?
 
Hi all,
So basically the lower the TDS the lower the GH is?
There isn't any direct comparison between them, but for most tap water they are correlated, because both TDS and dGH/dKH relate directly to the amount of Ca++ and HCO3- ions in the water.

The Ca++ and HCO3- ions both come from the dissolution of limestone (CaCO3) by rain-water, this may have occurred millions of years ago or it may have been geologically very recently. Most aquifers in the S. and E. of the UK are pretty pure limestones, and the same applies to reservoirs like Chew Valley Lake, Rutland and Grafham water etc. and most of the rivers (Thames, Great Ouse etc.) from which water is abstracted.

As you go N. and W. there are fewer limestones, and more rain, so water supplies are often from reservoirs in hard rock, like the Elan Valley, Thirlmere, Ladybower, Stitithians etc. and these provide softer water with lower TDS.

Although some compounds are added to water by the water companies (NaOH, phosphoric acid, sodium fluoride etc) they have a relatively small effect on TDS (although the NaOH is deliberately added to raise the pH above pH7).

This isn't necessarily true for other countries (<"USA">, New Zealand, the Mediterranean countries) where different geology can lead to different ratios of solutes in the water.

cheers Darrel
 
So you only used solution to test your cheap meter? And not because you needed to use it?

To satisfy my curiosity yes and to see what sort of accuracy the devices had. I also used it to calibrate my new device but it was basically spot on anyway.
 
To satisfy my curiosity yes and to see what sort of accuracy the devices had. I also used it to calibrate my new device but it was basically spot on anyway.
Ok thank you for the replys I appreciate it. So I won't need solution to calibrate my tds pen. This might sound stupid but the reading I am getting from mine is just numbers. Which is telling me I have a low TDS reading from my tap and in my tank water. What can I do to raise these numbers? Or do I not need to raise them?
 
Ok thank you for the replys I appreciate it. So I won't need solution to calibrate my tds pen. This might sound stupid but the reading I am getting from mine is just numbers. Which is telling me I have a low TDS reading from my tap and in my tank water. What can I do to raise these numbers? Or do I not need to raise them?
It is just a number. Do you know what your GH / KH are? If not I suggest you get a test kit to measure that. A TDS reading isn't going to give you any answers but rather point you where to look or give you an indication things have changed.
 
It is just a number. Do you know what your GH / KH are? If not I suggest you get a test kit to measure that. A TDS reading isn't going to give you any answers but rather point you where to look or give you an indication things have changed.
My water report is telling me my GH is 6.5 and kH is the same isn't it? But havnt tested my actual tank water for GH/kH

Cheers Lee
 
Funny to know actualy :) Don't you have an EC meter, but you happen to have a multimeter?

it might help to understand the EC meter a bit better, what it does and how the number it gives is created.
Think of Electrical conductivity, can not be determinated without knowing its resistance. Try this..

Fill a small square plastic container with a layer of water.

Now we need lenght, width and depth in cm.

Assume 30cm long, 20cm wide and 2cm water in it.

Take a multimeter and switch it to measuring Ohm (Resistance) symbol is

Touch both leads of the multimeter to the water one at each end of the containers lenght.

Assume we measure 33Ω

First we need the area of the width and depth: 20 x 2 cm = 40 cm²

Now we need to devide the lenght with Ω and the square to get at the conductivity in units of siemens per meter

30 / 33 / 40 = 0.0227 Siemens per meter.

Convert the conductivity to microsiemens per cm by multiplying by 10.000.

0.0227 x 10.000 = 227 µS

If you like to convert that number to PPM - TDS see bellow
https://www.lenntech.com/calculators/conductivity/tds_engels.htm

:thumbup:
 
Hi all,
How would I find that out. On my water report?
Yes you can, it is posted in your other thread, it has values for <"hardness (this is really the dKH) and calcium (Ca)">.
  • The hardness values (as mg l-1 of CaCO3) are min. 63, mean. 102, max. 177.
  • Calcium (Ca) (mg L-1) values are 18.3, 30.8 & 51.1 respectively.
  • Conductivity (microS.) is 160, 257 and 406.
  • Hardness is given as "slightly hard" and you have a "degrees Clark" hardness value of 7.14.
From the other thread.
As @Parablennius suggests that is a lot of variation in water hardness, so you have supplies from more than one source. Because you have virtually no nitrate in your supply the harder water is almost certainly from a deep limestone aquifer, and the softer water from a moorland reservoir.
I'll start with the degrees Clark hardness (degrees Clark is also called "English Degrees"), you can convert that to dKH/dGH by dividing by 1.24, so 7.14 equates to about 5.75 dGH/dKH. Again the working are back in the <"other thread">.
The best summary of water hardness I've found are still the ones on "the Krib" <"Water Hardness"> and <"Hardness (incl. History">, mainly because they include the history and definition of the units.
If you want to work out the maximum, minimum and mean values, this thread (I got the formulae etc from the "Krib threads") has the <"workings for my tap water at home">.

The main differences would be my tap water is a lot harder and much more consistent through-out the year (it always comes from a deep limestone aquifer). The home tap water is good for Cherry Shrimps and Vallisneria, but the rain-water (that I use in the tanks) is too soft for either of them in the winter, <"I also get a lot of shell attrition on the Ramshorn snails">.

cheers Darrel
 
Hi all, Yes you can, it is posted in your other thread, it has values for <"hardness (this is really the dKH) and calcium (Ca)">.
  • The hardness values (as mg l-1 of CaCO3) are min. 63, mean. 102, max. 177.
  • Calcium (Ca) (mg L-1) values are 18.3, 30.8 & 51.1 respectively.
  • Conductivity (microS.) is 160, 257 and 406.
  • Hardness is given as "slightly hard" and you have a "degrees Clark" hardness value of 7.14.
From the other thread.I'll start with the degrees Clark hardness (degrees Clark is also called "English Degrees"), you can convert that to dKH/dGH by dividing by 1.24, so 7.14 equates to about 5.75 dGH/dKH. Again the working are back in the <"other thread">. If you want to work out the maximum, minimum and mean values, this thread (I got the formulae etc from the "Krib threads") has the <"workings for my tap water at home">.

The main differences would be my tap water is a lot harder and much more consistent through-out the year (it always comes from a deep limestone aquifer). The home tap water is good for Cherry Shrimps and Vallisneria, but the rain-water (that I use in the tanks) is too soft for either of them in the winter, <"I also get a lot of shell attrition on the Ramshorn snails">.

cheers Darrel
The hardness values on my report. How does this contribute to my water? Probably a stupid question really but does this make up my GH? Or contribute to my TDS. I appreciate you replying Darrel if it wasn't for you I wouldn't know how to convert my hardness Clarke into GH and conductivity into TDS. All these letters and numbers are mind blowing.is calcium a big factor in my water. On my water report which ate the important ones I should be looking at. Conductivity/ calcium/ PH / hardness clarke/ which others. Also do I have to convert every reading on the report to get a ppm figure?

Cheers Lee
 
i'll leave the guys above to explain it all better than i can but to cut to the point, your water should be more than fine for red cherry shrimp to live and breed in. It's very similar to my tank parameters after my very soft water has added calcium added
 
Hi all,
but to cut to the point, your water should be more than fine for red cherry shrimp to live and breed in. It's very similar to my tank parameters after my very soft water has added calcium added
That would be my thought as well.
The hardness values on my report. How does this contribute to my water? Probably a stupid question really but does this make up my GH? Or contribute to my TDS.
It does both.

TDS
The ppm TDS value (really electrically conductivity) is a just measure of all the salts (ions) in solutions. What we call "water" isn't pure H2O, but a <"dilute solution with water as a solvent">.

Pure H2O is to all intents and purposes an electrical insulator, it doesn't conduct electricity. If you test DI water with a conductivity meter it will read less than 5 microS (3 ppm TDS), conversely sea water has a lot of salts (mainly salt NaCl, about 33 ppt.) and it is an efficient conductor of electricity, (it would have a conductivity of ~50,000 microS).

A lot of salts are highly soluble in water, including the ones we use a fertilisers. All plants, even terrestrial ones, can only take up nutrients as ions from solution.

Hardness
The assumption is that the hardness/dHG/dKH are the same, because they all relate to how much calcium carbonate (CaCO3) is dissolved in the water. One unit of dGH, and dKH, are both equal to 17.86 ppm CaCO3.

Limestone (calcium carbonate) isn't very soluble (technically it is only soluble in weak acids), but because rain water absorbs some CO2, it is a weak acid until it has dissolved some bases, almost always CaCO3 in the UK. The remaining, undissolved limestone, acts as a "buffer" that can go into solution and ensures that new rain water arriving becomes harder. This dissolution of limestone by rain-water is how you get caves, tufa springs and limestone pavement etc formed.

When water collects in limestone geology ("aquifers") it will become fully saturated with Ca and HCO3- ions, giving it a pH of pH8, a hardness of about 18dKH/dGH and a conductivity of 650 - 800 microS. If these values are higher you have other stronger bases present, if the aquifer values are lower there is some calcium carbonate present, but you might have very high rainfall, a very hard limestone (like the Carboniferous age limestone) or a sand-stone aquifer with only small amounts of CaCO3 present.

If your tap water doesn't have any carbonate buffering (dGH/dKH), and a low TDS value you can say that it has not encountered any limestone in its journey from rain-water to your tap. Because limestones are porous, upland reservoirs are almost always in non-calcareous rocks and these are the principle source of soft water in the UK.

cheers Darrel
 
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