# PPS-Pro, How to use a TDS meter?



## trong (Aug 8, 2006)

I've been using it and am very impressed with the growth of the plants. They grow so well i'm going to have to limit the # of species i keep do to the extra large sizes the plants are getting. It is my understanding you only need to change water when NO3 gets too high or TDS becomes too high. What is too high for TDS? I've seen mine between 150 to 350ppm.


----------



## Edward (May 25, 2004)

*Re: PPS-Pro?*

*How to use a TDS meter?*

The actual level is relative, there is no fixed numbers. It all depends on the water you start with. Dissolved elements cause TDS conductivity increase. DI water is about 0.01 uS, distilled water is 0.1 uS, RO is 1 uS and tap water about 200 uS (+/- 200). Let's say your tap is 150 and your aquarium is 450. Clearly such a large difference indicates a possible problem. It could be dissolving substrate, fertilizer overdosing, overfeeding etc. But if it goes to 300, stays there for months and the whole aquarium looks good then you know you got it right. It tells you if you have achieved biological balance and don't have to change water. In summary it is more about the rate of change per time then the actual numbers. Fish and also plants are very sensitive to TDS levels and fluctuations. Using TDS meters is cheaper, easier and faster then other water testing and once you understand your aquarium you know how to use it. 



Thank you
Edward


----------



## detlef (Dec 24, 2004)

*Re: PPS-Pro?*



Edward said:


> In summary it is more about the rate of change per time then the actual numbers. Fish and also plants are very sensitive to TDS levels and fluctuations. Edward


Edward,

how much a conductivity difference between tank water and water used for wc's do you consider tolerable/have no negative effects on plants?

As wc's typically induce high and rapid conductivity changes vs. slowly rising amounts of dissolved elements caused by overfertilization, dissolving substrate etc. shouldn't TDS be monitored more closely when the aquarist changes water?

Best regards,
Detlef


----------



## Edward (May 25, 2004)

Interesting question. 
I don't know if there were experiments done on this subject. From experience we know for example Cryptocorynes melt when conductivity suddenly changes. This could be either up or down. Fish go into shock and can die. I would speculate that 50 uS followed by several days to adjust could be the limit. 

Some substrates, because of acidic CO2 presence, dissolve so rapidly we can see +1000 uS in just few weeks time. PPS-Pro for example, is considered to be a lean fertilizing program and it already increases TDS 6 uS a day without plants. In a fully planted aquarium these nutrients are taken by plants and therefore no TDS increase is experienced.

Thank you
Edward


----------



## detlef (Dec 24, 2004)

Your answer seems to be another strong argument for keeping consistancy/ stable water parameters. Sudden changes should be avoided by all means.

Following your point of view I can also see a potential for growth problems when high amounts of nutrients are being fertilized as TDS will either sky rocket (not enough or no wc's at all) or likely fluctuate a great deal (with wc's). High conductivity changes might therefore be an inherent EI problem.


Anyway, thanks very much for replying and best regards,

Detlef


----------



## Snake52 (Dec 15, 2006)

*Re: PPS-Pro?*



Edward said:


> *How to use a TDS meter?*
> 
> The actual level is relative, there is no fixed numbers. It all depends on the water you start with. Dissolved elements cause TDS conductivity increase. DI water is about 0.01 uS, distilled water is 0.1 uS, RO is 1 uS and tap water about 200 uS (+/- 200). Let's say your tap is 150 and your aquarium is 450. Clearly such a large difference indicates a possible problem. It could be dissolving substrate, fertilizer overdosing, overfeeding etc. But if it goes to 300, stays there for months and the whole aquarium looks good then you know you got it right. It tells you if you have achieved biological balance and don't have to change water. In summary it is more about the rate of change per time then the actual numbers. Fish and also plants are very sensitive to TDS levels and fluctuations. Using TDS meters is cheaper, easier and faster then other water testing and once you understand your aquarium you know how to use it.
> 
> ...


Interesting, I have just bought a Milwaukee TDS monitor. I have well water with a TDS of 700ppm. Started using PPS Classic for about a week and the TDS of my tank water is usually 0-10ppm above that of my well water. I have constant water change with slow dripping off and on. Have Aquasoil Amazonia II, moderate plant load, 15 Neons 4 Cory cats, 6 Harlequin Rasboras, 6 Otos and a dozen cherry shrimps in a 90 gal., 260 watts PCs and presurrized CO2. pH is around 6.6.

My well water is very hard, so should I add anything to soften it or is it OK ? My pH swing is about 6.8-7.0 at night when CO2 is off.

I have just acquired a Hagen test kit and am waiting to calibrate it. So what should the optimum TDS of my tank water be ? Should it be about let's say 50 ppm or less, above that of my well water ? Looks like I am not dosing enough PPS ?? Thanks.


----------



## Edward (May 25, 2004)

Hi
Your well water is extremely high on dissolved solids at 700 ppm (700 ppm is ~1400 uS). This does not mean its bad, just very high on some minerals and if everything looks good in your aquarium and plants are healthy don't change anything, keep it that way. The continuous drip water change preserves favorable TDS stability. 

Thank you
Edward


----------

