tds meter help

jman23

Active Member
okay i just got a tds meter and when i test my tap water it comes out high 100s low 200s what should it be any help would be awsome
 

Shrubs First

Well-Known Member
okay i just got a tds meter and when i test my tap water it comes out high 100s low 200s what should it be any help would be awsome
Hey bro, 100-200 isn't considered very hard. It is mostly made up of carbonates and calcium/magnesium and
a bit of chlorine. Just make sure to factor that into your total TDS when you mix up nutrients. So like if you are
trying to achieve 700 ppm in your solution, add what the recipe would call for you to get to 500 so that the total
will equate to the 700 including the tap.
 

Shrubs First

Well-Known Member
okay thanks still dont get it 100% but i guess ill have to mess around with it
TDS means total dissolved solvents. So you're testing the concentration of the total dissolved solvents in comparison
the the water (parts per million or ppm). Depending on the scale of your unit (I'm not sure what brand you have) the number it shows on the
screen can mean several things. Because TDS is based off of EC (electrical conductivity) it is a converted number and
is scaled. EC is an easy number to work with because it is shown like .1 - 2.0 for concentration. On some meters 500 ppm
is 1.0 EC and on some meters 700 ppm is 1.0 EC. The EC is constant, the ppm's are scaled differently for different companies.

Find out what company your meter is and what scale it is on. A small plant will enjoy a soil EC of roughly .8-1.0 and large
vigorous plants growing fast will want a diet higher up into the 1.5-2.0 range.
 

curious2garden

Well-Known Mod
Staff member
TDS means total dissolved solvents.
Actually it means total dissolved solids. Solvent is the material the solid is suspended in.

Look at the nutrients you have purchased. Each brand usually gives recommendations. Take the recommendation and scale it back to 1/4 to 1/2 and see how your plants respond. You'll quickly learn where your plants are comfortable. Essentially in most suburban water the dissolved solids are calcium so nothing really nutritious for your plants. So let's say your fertilizer suggests a TDS of 400. Your water already has a base of 200 dissolved solids so if after you mix your fertilizer into your water it reads 400 ppm on your meter then you aren't giving your plants 400 ppm of the fertilizer but 200 of the fertilizer and 200 of whatever was in your water to begin with.

So to give your plants 400 PPM of your fertilizer your meter will need to read 600 that is 400 PPM of your fertilizer plus 200 PPM of whatever is in your water. I hope that helps.
 
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