• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

TDS meaning

Delapool

Member
Joined
27 Aug 2016
Messages
46
Location
Perth, Australia
So finally got a chance to try TDS meter.

Readings sounded good from feedback but are there any links that describes what TDS readings equate to for different environments I guess?

Tap was 240ppm. Tank was 250ppm.

Yet to find annual water report (which can’t be trusted as they say they mix up to 4 water sources from desalination to dams to groundwater) but might give an idea.

Tank has just finished re-cycling so had been large water changes to keep ammonia in check and dosed up to get some nitrates afterwards (got tired of reading 0) so tap and tank being close (?) seemed to make sense.
 
Should add I just keep rams, angelfish, loaches in with java fern, etc - not try to breed or anything, just out of interest.
 
TDS readings give the Total Disolved Solids reading. So anything that can dissolve in water will change the reading. Hence the slight increase in reading from the tap water to tank water, as the tank water will have more dissolced solids in it from the Scape plus any ferts added.
I have a TDS meter but never use it as I use EI fert dosing the weekly WC resets the tank.
If I did use the TDS meter I would just get a bigger reading pre WC than post WC.

But TDS meters useful for keeping some livestock.

Hope that helps
 
Last edited:
Hi all,
Tap was 240ppm.
It suggests the water is fairly hard. TDS meter are all really conductivity meters, and it just uses a conversion factor to change conductivity in microS to ppm TDS. The usual conversion factors are 0.5, where the salts are mainly NaCl, and 0.64 where most of the ions are from CaCO3.

So about 400 microS (DI water would be less than 10 microS and seawater is 53,000 microS)
Should add I just keep rams, angelfish, loaches in with java fern, etc - not try to breed or anything, just out of interest.
Should be all right, they won't breed successfully and you may find your Rams only live 18 month - two years.

cheers Darrel
 
Hi all,
Is there any range of say x to y to define soft, medium, hard, etc?
There isn't a direct conversion, but in freshwater you tend to get a range of common ions and they contribute most of the conductivity. When a salt dissolves you get an equal number of cations and anions (like Na+ & Cl-).

The conductivity of the water then depends upon how wet it is in your locality and the geology of the region. In the UK, in the drier S. and E., water is largely abstracted from <"geologically young limestone aquifers">, where it is fully saturated with Ca++ and 2HCO3- ions. In the N. and W. of the UK water is largely from reservoirs, which fill due to the higher rain-fall and impermeable nature of the rocks. There aren't many soft limestones, so the water doesn't collect many bases and has low conductivity.

In the UK conductivity and water hardness are fairly strongly correlated. Water softness and lower pH used to be strongly correlated as well, but all UK tap water is routinely treated to raise the pH above pH7 which stops lead (Pb) , zinc (Zn) and copper (Cu) from old pipes going into solution. Water treatment is usually by NaOH injection, which raises pH (it is a strong base you have a Na+ and a O-H in solution), but doesn't add any buffering (dKH or dGH). Soft alkaline water is pretty unusual naturally.

The ions in solution can differ in other countries, where you have an arid climate and/or active plate tectonics. You can also get a substitution of magnesium for calcium (<"dolomitization">) in limestones that have formed in evaporite basins. This is common in the <"USA">.

cheers Darrel
 
Back
Top