PH Measuring

[james24]

Is this info correct? Could use a bit of clarification.

1) When checking PH you should do it after adding nutrients to water. Depending on reading add PH up or down.

2) No, need to check PH of run off.

Now questions:

1)Should you check PH everyday before feeding/watering?

2)When, HOW, and how often do you check PPM/EC?

 

[RetiredMatthebrute]

im asuming your in soil...

first of all you shouldnt be feeding and/or watering every day...going to cause root rot problems unless your containers are drying out completly that quick which can happen but is un common.

if you are PHing your water/nutrient solution you shouldnt have to worry about testing the soil, as far as ppm/ec you should just have to test your solution once and know that x amount of nutrient solution in y amount of water gives z ppm. fill your watering container up, add a measured incriment. 1 tsp of nutrient solution..measure ppm now you have a base PPM counting any particles in the water you use..so say 1 tsp gives you a ppm of 450 in a 1 gal container.

then add another tsp of nutrient....now test ppm of water again...now you have 750 ppm.... so now you know that each tsp of nutrient solution raises the ppm of 1 gallon of water by 300 and your plain water probably has a ppm of around 150...if your not convinced add another tsp of nutrient and measure...should give you a ppm of 1050 +/- (theres no way it will be dead on but should be within 100 ppm +/- )

you will check your PPM/EC with a ppm pen....you can check runoff ppm but not really worthwhile, if your using chemical nutrients then you will want to flush your containers every 6 weeks with plain water = to 5x the container size...i.e a 3gal pot would get flushed with 15 gal of plain water. this will wash out any salt build up and keep you protected against lockout issues due to buildup...its not always necessary but a good preventitave measure.

so to answer your ??

1) yes, check ph of nutrient solution and adjust as needed before watering. doing this will ensure you maintain a good ph level in your soil. if you dont adjust the soil PH may change over time.

2) PH of runoff is irrelivant but if your soil starts off at the correct PH and you are PHing your nutrient solution before watering/feeding then the runoff should be pretty close to your desired level.

i think i covered all of it..

 

[james24]

im asuming your in soil...

first of all you shouldnt be feeding and/or watering every day...going to cause root rot problems unless your containers are drying out completly that quick which can happen but is un common.

if you are PHing your water/nutrient solution you shouldnt have to worry about testing the soil, as far as ppm/ec you should just have to test your solution once and know that x amount of nutrient solution in y amount of water gives z ppm. fill your watering container up, add a measured incriment. 1 tsp of nutrient solution..measure ppm now you have a base PPM counting any particles in the water you use..so say 1 tsp gives you a ppm of 450 in a 1 gal container.

then add another tsp of nutrient....now test ppm of water again...now you have 750 ppm.... so now you know that each tsp of nutrient solution raises the ppm of 1 gallon of water by 300 and your plain water probably has a ppm of around 150...if your not convinced add another tsp of nutrient and measure...should give you a ppm of 1050 +/- (theres no way it will be dead on but should be within 100 ppm +/- )

you will check your PPM/EC with a ppm pen....you can check runoff ppm but not really worthwhile, if your using chemical nutrients then you will want to flush your containers every 6 weeks with plain water = to 5x the container size...i.e a 3gal pot would get flushed with 15 gal of plain water. this will wash out any salt build up and keep you protected against lockout issues due to buildup...its not always necessary but a good preventitave measure.

so to answer your ??

1) yes, check ph of nutrient solution and adjust as needed before watering. doing this will ensure you maintain a good ph level in your soil. if you dont adjust the soil PH may change over time.

2) PH of runoff is irrelivant but if your soil starts off at the correct PH and you are PHing your nutrient solution before watering/feeding then the runoff should be pretty close to your desired level.

i think i covered all of it..

I will be using coco 70%/ perlite 30%

 

[mikeee420]

For your first two questions.. Yes check pH after adding nutrients. Nutrients will change the pH of your water so if you do it before adding nutes your reading will not be representative of what your plants are actually getting fed. For your second question, this is debateable, and what it ultimately comes down to how much effort you want to put in, and how much you care. Some theories are that the pH of runoff will be way off so it is invalid info, others say it's valid. Personally, I'm not sure, but I check it only if plants are showing a deficiency. A more accurate and accepted form of measuring the pH of the medium is the slurry test.. IF interested do a search on that.

Always check pH of what your feeding.

For ppms..to measure them you need a PPM meter. You should always check this.. both what your feeding and the runoff. Once again it comes down to how much you care... If you do measure PPMS of both what you put in and what comes out, you can get a basis of how your plants are eating. If its coming out with higher ppms than what you're putting in(150+ ppm over whats going in) then that means your feeding too heavily, and may want to cut back a bit. If it's coming out low, it means the plants are eating more than you're giving and you can safely raise your nute levels..


Another piece of advice. If you do decide to be meticulous about measuring these, I would suggest keeping a log of these numbers. If something comes up in 2 weeks where your plants are looking sad, you're able to look at your log and see what's been going on.

my .02

 

[DeeTee]

As for the first question, yes, I always check my ph before re using my nutrients after drain, as far as ppm's I only check when first mix nutrients, re use 2 sometimes 3 times but never check ppm's, I've yet to see any problems from not checking ppm's begore re use.

 

[lushgreen]

You should check pH before each feed. I grow in 100% coco and I feed once a day with full nutes until I get approx 15% run off (drain to waste setup).
If you plan to use a drip system with a reservoir then you'll still need to keep an eye on the res pH approx once a day as it does tend to wander upwards.

As I am running a drain to waste system I don't really need to check the EC of the feed solution as I know whats in it.

 

[james24]

You should check pH before each feed. I grow in 100% coco and I feed once a day with full nutes until I get approx 15% run off (drain to waste setup).
If you plan to use a drip system with a reservoir then you'll still need to keep an eye on the res pH approx once a day as it does tend to wander upwards.

As I am running a drain to waste system I don't really need to check the EC of the feed solution as I know whats in it.

What do you use to catch the run off and how do you gauge 15% run off if amount of water may vary daily?

I have seen some people say to just water once a day until you hear some dripping.

 

[lushgreen]

I measure the amount of feed water with a jug. Currently at week 3 of 12/12 I know my plants require 1.8L each to give me a 15 - 20% run off.
Once you get to know your plants you'll have a fair idea how much they require each week.