TDS & water hardness question

[Dave27]

I'm confused, could someone clear this up.

My hanna combo penn reads EC or TDS which is basically the same just different ways to measure the same thing correct?
EC readings are usually about dbl that of a TDS, meaning TDS of 200 will be a EC reading of 400.
This is water hardness, correct?

So if I get a reading of TDS 200 what does that mean?

And
When a water level of 3dh is asked for what would that be in a TDS reading.

Appreciate any help on this.

[Don Trinko]

Yes and no; A low TDS is soft water but the water you get from a water softener feels soft but typicaly has a high TDS. This is because the water softener replaces calcium salts with sodium or potasium salts. This makes the soap foam and the water feels "soft" but the TDS is high. Don T.

[Dave27]

I guess I'm thick between the ears.

So what is dh?

GH is general hardness
KH is Carbonate hardness

This breeding article I was reading calls for
" set the temperature at 27-28 degrees C ; Ph level at 6.5 ; hardness water at level 3 dH. "

[Graham]

dH* is degrees of hardness and is German for GH, which is ppm. It can also be gH*/ general Hardness

If you multiply dH by 17.9 you come up with ppm...........

They are a measurement of calcium and magnesium, where as TDS, total disolved solids is everything. That's why water can measure/test soft low GH/dH but still be high in TDS

KH... carbonate hardness, temporary hardness, alkalinity in just a measurement of carbonates and bicarbonates

[Dave27]

Thanks Graham!

[Patr1ck]

Also the EC reading is the true reading of your water (I have the same meter). The tds reading on your meter is just a conversion of EC. The conversion factor can be programmed into your meter. I changed mine to .81 conv. It was set at .50 conv from the factory. The reason that I changed it was because I use ro right and the table on the back of the jar (after doing the math) listed the recommended tds readings at 81 percent of the recommended EC readings instead of 50 percent.

Patrick