WATER PPM how do i know what it is? how do i test it?

ok from what i been reading the ppm in water is extremely important. i found this
http://www.ewg.org/tap-water/whatsinyourwater/MI/City-of-Detroit-Water-Department/0001800/

I dont know what my ppm is for regular tap water. i have also found this

600 PPm for week 1
900 PPm for week 2
1200 PPm for week 3
if you go over 3 weeks veg
1500 PPM week 4
1800 PPM week 5 and hold there
at bloom I flush and go to 1000 PPM week1
1300 ppm week 2
1600 PPM week 3
1900 PPM week 4

I dont know how true this is.

I also found this table for ppm



<A href="http://www.420magazine.com/gallery/data/829/PPM-EC-C.jpg" rel=lytebox target=_blank>

I guess my main question is how do i test PPM for water? and what is the correct ppm for each week of veg and bloom. I would really appreciate any feed back on this. thanks...

i don't test my ppm, but i do test my ph, and all i have to do for that is simply dip the tester into the water for a few moments, and wait for the number to settle down, and read.. simple as that.. i would imagine that a ppm meter is relatively similiar as a ph meter in this way..
what method of growing are you doing? ie, soil, hydro, ebb and flow, aero, etc..

ive done ebb and flow in the past and been succesful, but my buds were small. this time around im going to do ebb and flow but im going to pay attention to all the details. i think knowing your ppm would help you master your neuts.

yeA FORGET THE PPM. JUST BE SURE PH IS DEAD ON EVERYTIME WATERED. FORGET THE OOM

what is oom ?

yah, for your style of growing, knowing all the fine details is what makes the difference between a good grow, and a not so good grow.. i would take great notes throughout the entire grow so that if any problems arise, you have the data to know why it went wrong.. or even if things went good for you, you will be able to duplicate the results for the next grow..
i'm a dirtbag personally, so i'm not sure about the ppm;s for each week of growth, but i'm sure someone around these parts can help you out some more..
best of luck with the grows m8..

A PPM meter can be purchased for as little as $20. Knowing your PPM is very helpful especially for new growers. It helps you ensure that you are not over or under feeding. You nutrient line should come with a chart or have one online that tells you the target PPM for your stage of growth. This is just a guideline however as all strains are different. Also no one here can tell you what PPM you should be at, or what PPM your tap is starting at. It's different for every situation.

The real advantage to having a PPM meter is that you can monitor the levels over several days, and this will really give you an idea of how much food your plants want. Check it every 24 hrs and if the levels rise, then your plants drank more water than they ate food, so it's becoming more concentrated; they want a lower PPM. If the levels fall, then they have used more food than water and the solution is becoming less concentrated; they want a higher PPM. Idealy, over 24 hours you want the water to drop a bit, the ph to rise a bit, and the PPM to stay the same. Finding this balance takes a fair amount of experience.

Technically there is no such thing as a PPM meter. There are EC - Electrical Conductivity - and TDS - Total Disolved Solids - meters. Both work by measureing the conductivity of a solution. The TDS meter then converts the EC measurement to PPMs using one or more of up to 5 different conversion scales. This is why when ever anyone starts talking about PPM they also need to talk about what conversion scale is being used as this can have a huge impact on your nute concentrations. An EC of 2.0 can be either 1000ppm or 1400ppm depending on what scale you are using. If someone doesnt know what scale they are using then they are likely giving you uninformed or erronious advice that will most likely lead to dead plants in your garden. Do some research on EC and TDS meters so you know what you are looking at and what you are talking about. I tend to go by EC as it is less open to confusion and missinterpretation.

Example, say I tell you you should be running 1400PPM but I dont refer to the scale I am using. This is like me telling you that you need a board that is 5 long. Well without knowing if I mean 5 inches, 5 feet or 5 meters how does that advice help you? If I am mixing to 1400ppm using the .7 scale and you are using the .5 scale then you would end up mixing a toxic dose of nutrients that would have your babies crisping and dying in a mater of days. If you refer back to the chart you posted you will see that an EC of 2.0 can be 3 seperate PPM readings. Yes, its confusing and until the industry gets some standardization it will remain that way. Just read up on it and it will become a bit clearer. Truncheon makes a good EC meter that is easy to use and gives readings in Electrical Conductivity -EC, Conductivity Factor - CF, and both the .5 and .7 PPM scales.

i can not find a ppm meter, do u have a link for one ?

On to how you put it in practice. Once you actually know what you are measuring and how to interpret that data then you can begin to use that knowledge to mix a nute solution best suited to the needs of your plants. The concentration will vary based on what brand of nutes you are using and the strain of plant you are growing. This is not a one size fits all scenario. Nute manufacturers usually tell you to mix heavy so they can sell you more nutes. Most of the time you dont need that high a concentration. My plants are happy at an EC of 1.9 in both veg and bloom. Now the manufacturer calls for a concentration of 2.0 in veg and 2.6 in bloom but when I mixed the bloom recipe my babies turned crispy. A good rule of thumb is to start at about 50% of the manufacturers recommendation and work up from there till your plants are happy.

And dont get too hung up on PPMs. Youll just drive yourself crazy as most folks talking about PPMs are not talking about the same conversion scale (or even understand it) which is why you see such a variance in the information you get on this topic. I dont mean to sound condescending but there is just a lot of a bad info out there and it helps to be able to spot it. Many folks just like to present info to hear themselves talk and feel important. If someone giving you advice cant back it up with varifiable facts then they are likely talking out of thier ass.

well maybe we can make this thread sticky by adding educational and sutiable information reguarding ppm/ec. ive learned alot so far. The ppm is extremely important and if you going to be logging as i will you will be able to pinpoint progress and get a great yield. I been doing alot of research and as far as im concearened the water is just as important as the lighting. See my problem is im reading so much different stuff and like you said, its hard to decide what is fact and what is fake. May i suggest that the pros take some time to give examples and facts/tips to better understand ec/ppm, neuts. IN my eyes this is a science and more you have under control the less that can go wrong.

Here is a bit more detailed info on EC/TDS

While EC and TDS are often used synonymously, there are some important differences to note. EC, when applied to water, refers to the electrical charge of a given water sample. TDS refers to the total amount of substances in the water other than the pure H2O. The only true way of measuring TDS is to evaporate the water and weigh what’s left. Since this is near impossible to do for the average person, is it possible to estimate the TDS level by measuring the EC of the water. Every digital TDS meter in the world is actually an EC meter.
All elements have some electrical charge. Therefore, it is possible to closely estimate the quantity of TDS by determining the EC of the water. However, since different elements have different charges, it is necessary to convert the EC to TDS using a scale that mimics the charge of that water type. The following are the most common water samples, and for the COM-100, each has its own conversion factor:
KClotassium Chloride is the international standard to calibrate instruments that measure conductivity. The COM-100 is factory calibrated with a 1413 microsiemens solution is the default mode is EC-KCl. The KCl conversion factor is 0.5-0.57.442TMeveloped by the Myron L Company, 442TM simulates the properties of natural water (rivers, lakes, wells, drinking water, etc.) with a combination of 40% Sodium Bicarbonate, 40% Sodium Sulfate and 20% Chloride. The 442 conversion factor is 0.65 to 0.85.NaCl:Sodium Chloride is used in water where the predominate ions are NaCl, or whose properties are similar to NaCl, such as seawater and brackish water. The NaCl conversion factor is 0.47 to 0.5.Measurements in EC (µS) do not have a conversion factor, but do require the correct setting for the proper temperature coefficient.
Most HM Digital TDS meters other than the COM-100 use the NaCl conversion factor (avg. 0.5). Some products are available with the 442 conversion factor.
Is pinpoint accuracy always necessary when testing for TDS or conductivity?Usually not. TDS is primarily about range. For the majority of industries that require TDS testing, such as drinking water, aquaculture, hydroponics, etc. it is more important for your TDS levels to be within a certain range. There are a few industries that do require a precise ppm level, but that level is almost always zero. With the exception of colloidal silver, there is never a time in which someone needs an absolute precise level of TDS in their water.What is the difference between a parameter and a scale?A parameter is the characteristic being measured. A scale is a particular range applied to the measurement of that parameter. For example, temperature is a parameter. Fahrenheit or Celsius is a scale.Is "EC" a parameter or a scale?“EC” is a parameter. It stands for Electrical Conductivity. There are a number of scales used in EC, most commonly micro-Siemens (µS) or milli-Siemens (mS). For example, if a particular application calls for water with “2.0 EC,” this is an incorrect determination. Most likely, the application is calling for an EC level of 2.0 mS. 2.0 mS = 2000 µS.
This information is from this site http://www.tdsmeter.com/faqs/