Why is my TDS off charts???

Krixic · Jul 5, 2020

Im curious as to why my bucket of RODI water that I made the other day is saying that it is 145 x 10 on my TDS meter? Just the other day it was at zero. I mistakenly dropped a little salt in the bucket but did not think much of it. I use the water to rinse off some of my equipment and due to some suspicions I had from earlier I wanted to test the water again today. I checked the salinity and it was only 1.001 SG so is that why the TDS is so high? Will that really show up on the meter as x10? Im just trying to understand if my water is bad or whats going on, cause I am pretty confused.

Bender · Jul 5, 2020

Someone with more knowledge will help out but I do know salt will increase your TDS into the thousands. Odds are that's what your reading.

legrunt · Jul 5, 2020

TDS is usually read in parts per MILLION.
So yeah, a little goes a long way. 1.001sg does mean you dropped more than just a "little" salt in.

Krixic · Jul 5, 2020

legrunt said:
TDS is usually read in parts per MILLION.
So yeah, a little goes a long way. 1.001sg does mean you dropped more than just a "little" salt in.

I see, It was not a lot of water to begin with so I probably did not account for how concentrated it would get. Thanks for the help!

Krixic · Jul 5, 2020

Bender said:
Someone with more knowledge will help out but I do know salt will increase your TDS into the thousands. Odds are that's what your reading.

Gotcha! That makes more sense then.

legrunt · Jul 5, 2020

Just to help you get your head around the maths... 1 gram of salt in 1 million grams of water will get you a reading of 1 tds.

5 gallons is about 19liters. Which is 19000ml. Which is about 19000grams. Divide that by a million and you would need only 0.019 grams to register 1tds.
That would mean 27 grams of salt would be enough to get it to 1450 tds, which is what you are reading.

Does that sound like how much you dropped in?

Krixic · Jul 5, 2020

legrunt said:
Just to help you get your head around the maths... 1 gram of salt in 1 million grams of water will get you a reading of 1 tds.

5 gallons is about 19liters. Which is 19000ml. Which is about 19000grams. Divide that by a million and you would need only 0.019 grams to register 1tds.
That would mean 27 grams of salt would be enough to get it to 1450 tds, which is what you are reading.

Does that sound like how much you dropped in?

Not really haha. It was closer to 10 grams I would guess. To be fair, it was only about 2-3 gallons in the bucket so thats probably right on the money ratio wise.