I see alot of people here who have sick plants often around week three of flowering and most often what looks like Mg deficiency. I have also seen alot of people solve the persons problem by telling them to get a pH pen. I just wanted to offer a tip for people who are going through this.
First off let me make a few statements. Every meter is a little bit different. Meters need calibration regularly. Probes of meters need to be cleaned regularly. Most meters don't have a very long life span before unreliable. Not all peat based mix is the same, even from batch to batch from the same company. Don't trust the mix no matter how expensive or popular to be dialed in regarding pH and conductivity. You cannot get an accurate reading of your soil pH by runoff without knowing the original pH and ec of the mix before using it. Lets call this your base number or reading.
You must have a base reading before amending or planting in your mix.
First start with r.o. or filtered low to no ppm water. pH the water to 6 or 6.5 mine is always 6.5 out of the filter so I take my runoff readings at 6.5pH and 0 ppm of water (If I used 6pH my ppm's would go up from adding the pH down to the water.)If you don't have a base reading you will not get accurate readings of runoff period. Also to note, measuring runoff is not a science. However it can be accurate enough if done right. Measuring correctly requires consistency. you must use water with the same readings every time. You must have your meter clean and calibrated every time. Let's say you want to get a reading of pH and likely will flush it as it has been way off. Once the soil has reached field saturation (equal parts drain for amount of water added) your runoff readings are less and less trustworthy as the water column pulls the water down and out of the pot very quickly. As each nutrient varies in solubility, your runoff won't be an even mix of the nutes you provided. You may notice if you have had to flush before that you may get a ppm of 1280 for example from the first amount of water you run through, while the next bucket of water you put through reads 1410ppm. Seems odd the numbers would go up adding no ppm water to the mix but the reality is there are different solubilities for each nutrient so readings can jump back and forth at first. I can't tell you how much water to use to get a proper reading as i don't know your pot size. For the most accuracy do your runoff sampling at similar moisture contents each time. In other words if you test after a recent feeding with soil moist, then next time you test and the mix is pretty dry, you will have to add alot more water to the pot to achieve runoff. Obviously your results would be skewed as the first time you tested at near field capacity with a fresh nute topoff in the pot, next test, alot more water was used to reach field capacity for runoff without fresh nutes. In reality you tested differently each time.The level of repetition or consistency with how you measure directly effects the accuracy of your readings.
If this sounds like a bunch of extra bullshit when your crop is already enough work,but once you've had pH problems the extra work more than pays off.
I needed to pot up some seedlings into peat from rapid rooters recently and picked up a big of soilless mix that didn't have a nutrient charge, though many do. Instead getting it wet adding some lime and uppotting I measured runoff from the mix. The pH was 8.1 and the ppm's were at 2600. Sounds like a problem as the seedlings only need about 100-200 ppm's.
A while back I bought a bag of BioBizz light mix which gives a pH and conductivity reading of the mix right on the bag. I think it was 5.8 and 1.3ec. I tested it first and the pH was 4.3 with a ppm of over 3000. Wow what quality control, nice of them to mislead you into a false sense of whats in your mix. Last year I tried using Berger sounds like 'Berjer' I'm probably spelling it wrong. It was great pH 5.8 1000ppm's. I bought more later and the pH was way lower and ppm's higher.
If you don't test your soil before planting or adding amendments you might as well add your nutes blindfolded as your levels may be way off before you even start. Knowing this, rules of thumb like always add a teaspoon of lime to your mix don't seem quite right.Test first, then add nutes or amendments knowledgeably. Hope this helps someone
First off let me make a few statements. Every meter is a little bit different. Meters need calibration regularly. Probes of meters need to be cleaned regularly. Most meters don't have a very long life span before unreliable. Not all peat based mix is the same, even from batch to batch from the same company. Don't trust the mix no matter how expensive or popular to be dialed in regarding pH and conductivity. You cannot get an accurate reading of your soil pH by runoff without knowing the original pH and ec of the mix before using it. Lets call this your base number or reading.
You must have a base reading before amending or planting in your mix.
First start with r.o. or filtered low to no ppm water. pH the water to 6 or 6.5 mine is always 6.5 out of the filter so I take my runoff readings at 6.5pH and 0 ppm of water (If I used 6pH my ppm's would go up from adding the pH down to the water.)If you don't have a base reading you will not get accurate readings of runoff period. Also to note, measuring runoff is not a science. However it can be accurate enough if done right. Measuring correctly requires consistency. you must use water with the same readings every time. You must have your meter clean and calibrated every time. Let's say you want to get a reading of pH and likely will flush it as it has been way off. Once the soil has reached field saturation (equal parts drain for amount of water added) your runoff readings are less and less trustworthy as the water column pulls the water down and out of the pot very quickly. As each nutrient varies in solubility, your runoff won't be an even mix of the nutes you provided. You may notice if you have had to flush before that you may get a ppm of 1280 for example from the first amount of water you run through, while the next bucket of water you put through reads 1410ppm. Seems odd the numbers would go up adding no ppm water to the mix but the reality is there are different solubilities for each nutrient so readings can jump back and forth at first. I can't tell you how much water to use to get a proper reading as i don't know your pot size. For the most accuracy do your runoff sampling at similar moisture contents each time. In other words if you test after a recent feeding with soil moist, then next time you test and the mix is pretty dry, you will have to add alot more water to the pot to achieve runoff. Obviously your results would be skewed as the first time you tested at near field capacity with a fresh nute topoff in the pot, next test, alot more water was used to reach field capacity for runoff without fresh nutes. In reality you tested differently each time.The level of repetition or consistency with how you measure directly effects the accuracy of your readings.
If this sounds like a bunch of extra bullshit when your crop is already enough work,but once you've had pH problems the extra work more than pays off.
I needed to pot up some seedlings into peat from rapid rooters recently and picked up a big of soilless mix that didn't have a nutrient charge, though many do. Instead getting it wet adding some lime and uppotting I measured runoff from the mix. The pH was 8.1 and the ppm's were at 2600. Sounds like a problem as the seedlings only need about 100-200 ppm's.
A while back I bought a bag of BioBizz light mix which gives a pH and conductivity reading of the mix right on the bag. I think it was 5.8 and 1.3ec. I tested it first and the pH was 4.3 with a ppm of over 3000. Wow what quality control, nice of them to mislead you into a false sense of whats in your mix. Last year I tried using Berger sounds like 'Berjer' I'm probably spelling it wrong. It was great pH 5.8 1000ppm's. I bought more later and the pH was way lower and ppm's higher.
If you don't test your soil before planting or adding amendments you might as well add your nutes blindfolded as your levels may be way off before you even start. Knowing this, rules of thumb like always add a teaspoon of lime to your mix don't seem quite right.Test first, then add nutes or amendments knowledgeably. Hope this helps someone
