Understanding Water Report.

[Steve Newman]

Hi,

Can someone please help in giving me basic Gh,Kh and Mg and any other worthy parameters from this report and/or links to calculators to work it out myself.

https://www.southwestwater.co.uk/siteassets/documents/water-quality/2022-water-quality-reports/zpl10-littlehempston-and-tottiford.pdf

New to the area and freshwater, having kept marines for 20 odd years I am struggling with this. I need to know what fish and plants would be suitable fora 150ltr planted cube.

Regards

Steve

 

[John q]

Can someone please help in giving me basic Gh,Kh and Mg and any other worthy parameters from this report

Hiya Steve,
From that report we can only get Ca levels which are 11mg/l. But a bit of detective work leads me believe the water around your area is fairly soft, around 2dGH (based off a random postcode in that area TQ9 6LU), that would give us an estimated 2mg/l or less of magnesium. I'd imagine dKhH around 2.

Seems like you have lovely water that just needs a smidge of calcium, a smidge of magnesium and then you should be able to keep the majority of fish or plants.

 

[dw1305]

Hi all,
Welcome to UKAPS,

Can someone please help in giving me basic Gh,Kh and Mg and any other worthy parameters from this report and/or links to calculators to work it out myself.

From that report we can only get Ca levels which are 11mg/l. ,....... Seems like you have lovely water that just needs a smidge of calcium, a smidge of magnesium and then you should be able to keep the majority of fish or plants.

What @John q says. It looks to be water from a reservoir on Dartmoor somewhere, that is why the nitrate (NO3-) value is so low (max. 4.5 ppm (mg / L)). The <"higher pH"> and phosphate (PO4---) values are from added compounds to <"control the solvency of heavy metals">.

The only proviso would be that the n = 355 conductivity samples are quite varied, which suggest that it may occasionally <"have a dash of harder water">, this isn't reflected in the values from the n = 12 calcium (Ca) samples.

You can assume you won't have much magnesium (Mg) <"for geological reasons">, so that 11 mg / L calcium equates to 11 / 7.143 = 1.54 dGH, the maths is in <"CO2 gaseous equilibrium with atmosphere">.

If you assume that all the calcium came from the dissolution of limestone (CaCO3)? You would also have 1.5 dKH as well.

cheers Darrel

 

[dw1305]

Hi all,

having kept marines for 20 odd years I am struggling with this

Easier in a lot of ways, because water changes aren't an issue and we have access <"to higher plants">, which are very effective at depleting levels of nutrients. <"Floating, or emergent, plants"> are particularly useful as nutrient reduction aids. As an example of the differences between marine and freshwater, a filter that is a <"nitrate (NO3-) factory"> is exactly what we want.

Chemical testing is generally more problematic in freshwater, both because we are have a <"much more variable medium"> and because freshwater is a lot less <"salty">.

cheers Darrel

 

[Steve Newman]

Thanks for the responses, yes Torquay ( TQ2) is a softwater area, I thought my Fresh water test kit was wrong, it came up with;
Ph 6.5
Gh 2.0
dKh Zero

So from the above contributors; thank you all.

Ph 8.25
Ca 11mg/l
Gh 2.0
Mg 2mg/l or less.
dKhH around 2.

Seems like you have lovely water that just needs a smidge of calcium, a smidge of magnesium and then you should be able to keep the majority of fish or plants.

Next question; How much smidge? and which smidge additives to use?

Regards

Steve

 

[dw1305]

Hi all,

How much smidge? and which smidge additives to use?

About 5 ppm magnesium (Mg)? The exact amount <"isn't decisive">.

<"Epsom Salts"> (MgSO4.7H2O) is the usual choice, you can use the <"Nutrient Dosing Calculator">, but it is pretty much 10% Mg <"so the maths>" is pretty straightforward.

cheers Darrel

 

[John q]

Next question; How much smidge?

Well technically a smidgen is 44 driblets or 176 iotas.
But if you want precision adding 7.61g of magnesium sulphate to your 150ltr tank will raise the Mg levels by 5ppm, which I'd agreed with @dw1305 is a good number to aim for.

Once you've dosed the initial tank volume you then only need to target the amount of water you change, ie if you change 75ltrs add in 3.8g with the water that's added to the tank.

it came up with;
Ph 6.5
Gh 2.0
dKh Zero

Were these readings taken from the tap or tank, if from the tank are you using aqua soil?

 

[Steve Newman]

Were these readings taken from the tap or tank, if from the tank are you using aqua soil?

I thought it may have been serveral tads.

From the tap, water not allowed to stand, was just suprised to get such low readings, used to Bristol or Thames water, hard as iron.

Thanks for the calculations.
Regards
Steve

 

[dw1305]

Hi all,

was just suprised to get such low readings, used to Bristol or Thames water, hard as iron.

If you had aquifer water it would be hard (from the Torbay limestones), but because it is from a reservoir on Dartmoor, it has very few solutes of any kind.

cheers Darrel

 

[John q]

Delete.