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Spotless water...help me understand

Where the hell do you put 147 litres or 147 kilo's of water! Do you have a truck or something?
 
@Kaliilo these threads might be of interest.

Have a look at <"conductivity datum">.

cheers Darrel
Thanks so much for the links guys, ill have a read through
 
Can i quickly ask, it was suggested I get a TDS meter which im happy to do but I actually dont know what im looking for in a pure water/tap water mix. Am i using it to ensure total dissolved solids remain low or just for changes? (the job I do means I tend to focus on trends rather than one off readings of things). I will be starting the change over to 50/50 as of tomorrow as the tank is empty of livestock. Thanks for the input guys its all been really helpful.
 
Hi all,
Can i quickly ask, it was suggested I get a TDS meter which im happy to do but I actually dont know what im looking for in a pure water/tap water mix.
Just <"dip the meter into your tap water">. Because of the <"Geology of SE England"> you will a reading somewhere near 400 - 500 ppm TDS (~600 - 700 microS) and that will equate to ~17 dGH and 17 dKH (there is no implicit relationship between <"hardness and conductivity">, but our water mainly comes from limestone aquifers and is fully saturated with calcium (Ca++) and bicarbonate (2HCO3-) ions).

The RO water will read less than 10 microS (~ 6 ppm TDS) and as you mix them together <"conductivity, hardness and alkalinity will all decline in direct proportion to the amount of RO water added">, so 50 : 50 mix will give water with half the conductivity, hardness and alkalinity of your tap water.

cheers Darrel
 
Hi all,

Just <"dip the meter into your tap water">. Because of the <"Geology of SE England"> you will a reading somewhere near 400 - 500 ppm TDS (~600 - 700 microS) and that will equate to ~17 dGH and 17 dKH (there is no implicit relationship between <"hardness and conductivity">, but our water mainly comes from limestone aquifers and is fully saturated with calcium (Ca++) and bicarbonate (2HCO3-) ions).

The RO water will read less than 10 microS (~ 6 ppm TDS) and as you mix them together <"conductivity, hardness and alkalinity will all decline in direct proportion to the amount of RO water added">, so 50 : 50 mix will give water with half the conductivity, hardness and alkalinity of your tap water.

cheers Darrel
Ahh fantastic thanks Darrel. They are only a few quid so ill grab one and just keep an eye on any wildly differing results. Quick question for you....using a calculator I got my hardness at 19degrees but this says 16. Which am I at?
Screenshot 2023-06-08 141453.png
Screenshot 2023-06-08 141419.png
 
Hi all,
using a calculator I got my hardness at 19degrees but this says 16. Which am I at?
The water company one should be right, but our water is always going to be about 17 - 18 dGH ("degree German"), purely because of the <"carbonate ~ CO2 equilibrium">.

I'd note that they only took one reading, and your water might vary a little bit through the year (values higher in the summer, lower in the winter) dependent on how deep the aquifer is, but generally you can only get harder water if you have <"another source of hardness">, other than CaCO3.

All the derivations, for the different units, are in this thread by Larry Frank at the Krib -<"Water Hardness">

You can use the 117 mg/L Ca value or Total Hardness value (292.5 mg/L) to <"work out dGH">.
1dGH = 17.86 ppm CaCO3 and 7.143 ppm Ca ............
So 117 / 7.14 = 16.39 and 292.5 / 17.86 = 16.38.

The alkalinity (dKH) should give you the same value, but it is slightly lower in this case 258 / 17.86 = 14.45 , possibly because it was taken from a different water sample.

cheers Darrel
 
Hi all,

The water company one should be right, but our water is always going to be about 17 - 18 dGH ("degree German"), purely because of the <"carbonate ~ CO2 equilibrium">.

I'd note that they only took one reading, and your water might vary a little bit through the year (values higher in the summer, lower in the winter) dependent on how deep the aquifer is, but generally you can only get harder water if you have <"another source of hardness">, other than CaCO3.

All the derivations, for the different units, are in this thread by Larry Frank at the Krib -<"Water Hardness">

You can use the 117 mg/L Ca value or Total Hardness value (292.5 mg/L) to <"work out dGH">.

So 117 / 7.14 = 16.39 and 292.5 / 17.86 = 16.38.

The alkalinity (dKH) should give you the same value, but it is slightly lower in this case 258 / 17.86 = 14.45 , possibly because it was taken from a different water sample.

cheers Darrel
Much appreciated Darrel, apologies for the million questions. Biology im good at, chemistry...not so much:lol:
 
Hi all,
chemistry...not so much
I'll be honest <"I still struggle">, and often have to <"ask a chemist"> and even then, often I need them to break down their answer into understandable (for me) chunks that I can fit together for myself, a bit like a child learning how to use Lego.

cheers Darrel
 
Hi all,

I'll be honest <"I still struggle">, and often have to <"ask a chemist"> and even then, often I need them to break down their answer into understandable (for me) chunks that I can fit together for myself, a bit like a child learning how to use Lego.

cheers Darrel

Darrel, With the chemistry bits I often feel like I am still at the stage of learning wood cube sorting.... :)

71GCgjcxt2L.jpg


Can i quickly ask, it was suggested I get a TDS meter which im happy to do but I actually dont know what im looking for in a pure water/tap water mix. Am i using it to ensure total dissolved solids remain low or just for changes? (the job I do means I tend to focus on trends rather than one off readings of things). I will be starting the change over to 50/50 as of tomorrow as the tank is empty of livestock. Thanks for the input guys its all been really helpful.

Yes, get a decent TDS meter. It's a great tool to gauge the overall stability of your tank - for instance in-between water change (WC) you do not want to see your TDS go up much (which is usually the case when you have too much build up of broken down organic material or if you have leaching hardscape, buildup of minerals etc.). And of course, to make sure you get the mixing right for your WC water. Also keep in mind that going 50/50 Tap/RO will only lower your dGH and presumably dKH to about 8... which is a good start for sure but still quite hard. I would try and aim for a bit higher RO content like 70% and 30% tap - this will bring you down to about 5 dGH / 5 dKH - even more livestock and plant friendly and also fine for invertebrates if you should choose to keep shrimps.

Cheers,
Michael
 
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Darrel, With the chemistry bits I often feel like I am still at the stage of learning wood cube sorting.... :)

View attachment 206497



Yes, get a decent TDS meter. It's a great tool to gauge the overall stability of your tank - for instance in-between water change (WC) you do not want to see your TDS go up much (which is usually the case when you have too much build up of broken down organic material or if you have leaching hardscape, buildup of minerals etc.). And of course, to make sure you get the mixing right for your WC water. Also keep in mind that going 50/50 Tap/RO will only lower your dGH and presumably dKH to about 8... which is a good start for sure but still quite hard. I would try and aim for a bit higher RO content like 70% and 30% tap - this will bring you down to about 5 dGH / 5 dKH - even more livestock and plant friendly and also fine for invertebrates if you should choose to keep shrimps.

Cheers,
Michael
Really helpful thanks so much...I think those ratios would be much better. Im starting the water changeover this weekend as life got in the way lol so Ill start slowly but ill aim for about 70/30. Its only 60l so still not a ton of water at 70% :)
 
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