Help Newbie here/ yellowing leaves

my water is pretty hard here in the socal the PH was at 8 and i'm having a hard time getting it to stay at or around 5.5, I usually have to add PH down after a feed to balance it out again for the next feed. I'm not using any nutriemts yet wanted them to be healthy first. it's been about 2 weeks since I transfferd them to the big pots. I bought a ec/tds meter and out of the package and into the res it read 16, I have no idea what that means.. i'm not sure if i need to calibrate it or how to read it. Please help me understand how to use my meter or what i'm failin at here.

To get an EC value, multiply the ppm reading by 2 and divide by 1000.
Thus, if your EC is 1:
1*1000/2= 500 ppm.
And if your ppm is 500:
500*2/1000= 1 EC

So if your ec is 16 then 16*1000/2= 8000ppm I don't think thats right. Does it read 1.6?
On the other hand 16 ppm sounds like r/o filtered water. what are you measuring?

well looks like u better feed them then, they r starving for nutes & r already N deficient!

Cruzer i'm not sure what you mean by what i'm measuring. The water I believe is R/O water I bought it from the store with the thoughts of having a better ph since our tap is so high, but it was no different. I stuck the meter in again to make sure and it's still reading 16. I deff think you're right theexception they do need some N, but i really want to know how to use my ec meter properly to keep from making any more mistakes.

ec measures electrical conductivity between salts. salts are nutrients. so that measure how strong your nutrients are.
pH is a measurement of how acidic the solution is.

Look at it this way, ec or ppm tells you the amount of the food you are feeding them, pH is like the salt and pepper.
Too much of either one and you wouldn't eat the food right? same goes for plants.

tds means total dissolved solids= food/nutrients
proper pH of the water allows the plant to uptake the nutrients.

so your meter is not a pH meter. it just measures ec/tds
the amount of tds in r/o is anywhere from 10 to 30. Hell my tap is close to 300

Ph of my tap is 7.5 Now r/o is not pH ballanced and when I get it from the store it is about 6.0
So its two separate readings. You want ec/tds at about 600 and pH at about 5.8 right now.

I use the drops to test my ph and the water alone was at 8 and above, then I added some ph down which contains sulfuric acid and brought it down to 5.5 to 6. the tds meter I just got today and stuck it in the res to get 16 the tap read 33. now i added about 1 1/2 tsp of flora noca grow 7-4-10 (btw I have no idea what the 7-4 -10 mean). the meter came with very little instructions but it says it's a tds meter cd-301 and the range is 10/1990 ppm. i dunno i thought my meter was a ec meter and a tds but i'm not really sure it says ec/tds/cf meters with atc on the lil pamplet. HA HA i'm so confused.. after adding the nutes the ph was at a 6.

OK, so here is the deal, you have a tds meter to check nutrient solution strength by PPM (parts per million) of total dissolved solids (tds) and drops to check pH. with ph up and down (baking soda and vintager work too) to adjust it. You're golden man.

You wanna always add your nutrients before adjusting the pH cause nutrients will change it and there is no reason to do it twice.
Now, after adding nutrients to r/o water and adjusting the pH you checked it with the tds meter and got 33. if that meter is working properly you must have a huge res. I have use flora nova grow. 3 teaspoons not table spoons in 4 gallons got to 500ppm I think.
How big is your res?

btw, NPK rating (or N-P-K) is used to label fertilizer based on the relative content of the chemicals nitrogen(N), phosphorus(P), and potassium(K)

this is the pamplet

my res is pretty big but I only have about 5 gallons in it right now and maybe a lil less than gallon in the bottom of each bucket.

Hum, Ya know, by looking at the back I see several different models so I gotta think that package is used for all of them. Looks like yours is listed with a x10 next to it. I'm not sure but maybe that means to times it by 10. So 33 would mean its 330ppm. that sounds about right.

How big is the res you added 1 1/2 table spoons of nova grow to?

That sounds about right then. six gallons or so.
3 teaspoons is equal to a table spoon.

ok cool so 330 is chill for them great! Thanks a lot man you really helped out! I think I was making that pamplet a lit more difficult to read the needed ha ha. If you're in the socal area i'd love to smoke ya down once this harvest is said and done for all your help.

Ec......tds .........ph.........WTF! YOU GUYS ARE MAKING THIS SO CONFUSING! JK! sou ds like someone was high and playing with his water! Im a newbie myself and my question is : are baking soda and vinegar ok to ph with? That's what I havebeen using and its working well!

No problem man, glad you got a handle on it.
Sometimes all it takes is looking at it from a different perspective. Well, this puzzle solved, have a good grow.