# Parameter query for CRS



## Rivachaz (24 Jan 2021)

Hi Everyone,

First time post here , bear with me 😀👍

I have a conundrum,
My tank for crs has the following parameters:
Ph6.7
Gh 6
Kh0
Nitrate 0
Tds 146
Using shrimpking active soil 
Salty shrimp gh+

I need to do a 10-20% water change ,
Yet I cannot get new water quite right.
Using a hm calibrated tds meter I get the gh to 6
And yet the tds is only showing around 86-90.
RO source is 0 tds.

Do I need to match the TDS in the bucket to the old tank water? If so then by adding more salty shrimp Gh+ To the new water , the tds will rise to a good 130-135 yet the gh then increases  to 7 gh?
Would that be to hard/high for crs?

What should I aim for with the new water? a lower closer matching gh of 6 (TDS86-90) or a higher Tds of 130-135 
(Gh7)?, or is that to high?

My original wat tds in the tank doesn’t hardly move from one week to another tds 145

Which is more important ? Tds of 140 (gh7) or the Correct gh6 yet lower tds?

Sorry to confuse, or am I just over thinking things and just get the gh to say 6 or even 5? And ignore the tds reading ? 

Thanks
Andrew


----------



## Zeus. (24 Jan 2021)

Rivachaz said:


> Salty shrimp gh+


this stuff salty shrimp ?


----------



## Rivachaz (24 Jan 2021)

Yes correct that’s the exact brand .


----------



## dw1305 (24 Jan 2021)

Hi all, 


Rivachaz said:


> Using a hm calibrated tds meter I get the gh to 6
> And yet the tds is only showing around 86-90.


A bit of strange one, but the <"ppm" value recorded by a TDS meter"> isn't the same as the ppm (mg/L) (of divalent cations) used to <"work out dGH">. 

I'd just go by the electrical conductivity value, it is a lot more straightforward The conversion factor the meter uses, to "convert"  microS to ppm TDS, is usually 0.64 so 100 microS is ~ 64 ppm TDS.

cheers Darrel


----------



## Rivachaz (24 Jan 2021)

Ok, thanks for the help, do I watch the gh and pitch for 6gh or the tds measurement?


----------



## Zeus. (24 Jan 2021)

Son was asking about this Shrimp King Bee salt just the other day so integrated it into the IFC calculator in a new remin clone program to save him having to over the odds for salts



Interesting how comparing it with Salty shrimp the same mass gets a different gH



Would be nice to get the Ca:Mg ratio of these products, in the Safety Data sheets all they mention is the calcium chloride content and that varies +/-10% which could well explain why your salt isnt quite hitting the parameters it claims


----------



## Rivachaz (24 Jan 2021)

Ah ok , that’s why perhaps ?

So should I lean towards just getting the gh at say 6 and forgot the tds measurement ?


----------



## Nick potts (24 Jan 2021)

I would go with Darrels suggestion of using TDS, aiming for somewhere around 120ppm.

Only reason is that TDS is a lot quicker and more accurate than testing the GH everytime.


----------



## Rivachaz (24 Jan 2021)

That calculator looks the dog balls , could you email me the calc?


----------



## Rivachaz (24 Jan 2021)

Ok I’ve made a batch of RO of 0 TDS , and gotten the tds to exactly 120, I then took a gh reading using api gh water test and it shows as gh of 7??🥺 is this right? Isn’t 7 to high?

Perhaps it’s the gh api test that wrongly giving 1 gh above what the actual is ? (6gh) ?

Any other water tests brands I could cross test against to see if it’s actually reading a gh of 7 at 120tds ?

Am I missing something obvious ?


----------



## Nick potts (24 Jan 2021)

Rivachaz said:


> Ok I’ve made a batch of RO of 0 TDS , and gotten the tds to exactly 120, I then took a gh reading using api gh water test and it shows as gh of 7??🥺 is this right? Isn’t 7 to high?
> 
> Perhaps it’s the gh api test that wrongly giving 1 gh above what the actual is ? (6gh) ?
> 
> ...


I don't keep crystal shrimp, but 6gh seems to be the upper range quoted for them.

Looking at the salty shrimp power, it says 200µS +- 50µS will give you 6GH, so anywhere from 96 to 160PPM TDS, taking the lower value of 96PPM for 6GH you wouldn't be far off with your 90TDS 6GH water?


----------



## Rivachaz (24 Jan 2021)

Just found a hardness converter online:
5gh gives 83.5 TDS
6gh gives 100TDS
6.5 gives 120TDS

Does this seem right guys? If I pitch for 100 tds
Would that be ok?


----------



## Rivachaz (24 Jan 2021)

6 gh ok (100tds to pitch for ) ? Or 5 gh for crs?


----------



## dw1305 (24 Jan 2021)

Hi all,


Rivachaz said:


> Just found a hardness converter online:
> 5gh gives 83.5 TDS
> 6gh gives 100TDS
> 6.5 gives 120TDS
> ...


Yes, I'd aim for 100 ppm TDS.  I like conductivity meters because conductivity is a linear scale and the meters are pretty straight forward to use and maintain. You could only <"really calibrate the API dGH"> test by making a standard with a salt like calcium chloride (CaCl2.6H2O).

I'm not a CRS keeper, but I'll copy in @Iain Sutherland, he has a thread that may interest you <"Taiwan Bee not so......">.


Rivachaz said:


> Ok I’ve made a batch of RO of 0 TDS , and gotten the tds to exactly 120, I then took a gh reading using api gh water test and it shows as gh of 7??





Rivachaz said:


> So should I lean towards just getting the gh at say 6 and forgot the tds measurement ?


If you feel happy with @Zeus.'s calculator and <"dry salts"> you can make your own mixes, if you don't you can carry on with "Salty Shrimp" and aim for a conductivity value that your shrimps are happy with.

cheers Darrel


----------



## sparkyweasel (24 Jan 2021)

DH expresses the hardness in terms of how much CaO would give that level of hardness. If the shrimp salt is using CaCl2 for the hardness, the TDS would be different to get the same level of hardness. So there is often a difference between measured hardness and hardness calculated from TDS.


----------



## Rivachaz (24 Jan 2021)

Ok to sum up as such should I aim for 6gh at 100 TDS reading on the tds Meter ?


----------



## dw1305 (25 Jan 2021)

Hi all, 


Rivachaz said:


> Ok to sum up as such should I aim for 6gh at 100 TDS reading on the tds Meter ?


That would sort of be the point, you may not be able to get 100 ppm TDS and 6 dGH.  I'm not a great believer in "magic numbers".

I would just ignore the dGH value and use the TDS value, it is a lot more straightforward. 

cheers Darrel


----------

