TDS

[Folta]

I got my meter in the mail today! I did a few tests - tap water upstairs, tap water downstairs, and distilled water that I had bought a few days ago.

 

Upstairs tap : 180

Downstairs tap : 195

Distilled water : 002

 

 

I started my reef back in march, and have only used tap water from downstairs the whole time. Last friday I bought 4 gallons of distilled water from the grocery store (as I need to hook up my ro/di but still haven't done it yet). I haven't done any water changes with the distilled, but I have been using it for top off (decided to never use straight tap water ever again for the reefs I keep) - things are already consideribly looking better. My blue tort is showing full polyps, the birds nest is showing its polyps again, the milli, the leather... all just look much better. I wish I never listened to the advice of all the LFS's I went to when I started it - "Tap water for Montgomery county is great, so you can use it without an ro/di unit." :o

 

Anyway, is there a way to get a reading of TDS on the water in my tank now? Or can I only use the meter for freshwater?

[xabo]

Anyway, is there a way to get a reading of TDS on the water in my tank now? Or can I only use the meter for freshwater?

 

Freshwater only.

[Folta]

Ok, thanks for the reply!

[Folta]

On this topic, what would be considered 'good', and 'bad'... range wise...

 

for example:

 

0-20 TDS good, > 20 bad

- or -

0 - 100 TDS good, > 100 bad

- etc -

[stank]

With your tap water being in the 185 tds range, the water out of your r/o should read 1-2 tds . when it starts to read over 5-7 tds you might want to replace some filters.

[Guest Larry-T]

I reaslly don't see anything wrong with using water that is under 200 TDS. You've got to realize that the reading is 200 Parts Per Million, where the TDS of a tank at a SG of 1.023 is well over 30 Parts per THOUSAND, or 30,000 PPM. So plus or minus 200 out of 30,000 is about the same fluctuation you get with a 1 degree F change in temperature. It's simply not significant.

[steveoutlaw]

Do any of the LFS sell any calibration fluid for the TDS meters?

[HowardofNOVA]

TDS - Total Dissolved Solids are only reading Minerals in the water, NO MATTER WHAT THEY ARE, Conductivity Meters do the same thing.

Readings of anything over 10 IMO means time to replace your filters, PERIOD!

 

The entire idea about using RO/DI units is to remove ALL trace solids and chemicals OUT of the water before you put them either in the tank on Topoffs or mixing with your favor Salt for water changes and nothing else.

 

Only PURE water is what you want to put into your tanks, nothing else. City waters have Chlorine, Phosphates, Heavy metals, etc in them. ALL not good for SW Corals and Fish. Anything less and your fooling yourself.

 

I have a NIH approved Conductivity Meter that when the readings reach 2 milo siemens per millimeter I believe, its time to change the DI Unit. When I test my water and the RO unit is reading over 10, time to replace it.

 

Remember, anything more than that and heading for Algae Blooms, Stressed Corals and more problems.

 

REMEMBER: KISS Method.

It always works.

Howard

[craby]

Larry-T

"So plus or minus 200 out of 30,000 is about the same fluctuation you get with a 1 degree F change in temperature."

 

This is not comparing apples to apples as the 200 ppm of "Total Dissolved Solids" in the tap water are unwanted solids & the 30,000 ppm in the tank are beneficial salt & trace elements.

[HowardofNOVA]

Just to give you an example, if you run Mixed SW through my Conductivity Meter, you will get a reading around 55-60 milo siemens, again, it's reading free flowing solids in the water, but can't tell you whether they are good solids or bad like phosphates or chlorine.

[Guest Larry-T]

According to some of the analyses I've seen, there are far more than 200ppm non-beneficial solids in most of the commercial salts like Instant Ocean and Coralife. As far as algae blooms are concerned, the orthophosphates which cause most of the problems are not taken out by commercial DI or RO units. You simply have to manage them or else do a lot of extra processing to purify your water through precipitation and other means. Since I spent too many years in a pollution control lab, I'm more comfortable adapting and acquiring what will work in my water than trying to spend thousands of dollars setting up a small scale version of a commercial treatment plant.

 

If you want to check out specifics, you should get a copy of your water department's analysis. They send me one every year and I don't see anything to worry about.

 

 

 

Larry-T

"So plus or minus 200 out of 30,000 is about the same fluctuation you get with a 1 degree F change in temperature."

 

This is not comparing apples to apples as the 200 ppm of "Total Dissolved Solids" in the tap water are unwanted solids & the 30,000 ppm in the tank are beneficial salt & trace elements.

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[Guest Larry-T]

Chlorine and orthophosphate are not, as far as I can tell, conductive enough to give you a reading. Chlorides and nitrates of various minerals will, but not the more exotic materials.

 

 

Just to give you an example, if you run Mixed SW through my Conductivity Meter, you will get a reading around 55-60 milo siemens, again, it's reading free flowing solids in the water, but can't tell you whether they are good solids or bad like phosphates or chlorine.

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