Okay, so I've researched and researched and can't get a straight consistent answer. When approximating your soils current PPM/TDS, I have always done it like so: I prepare my nitrient solution (Fox Farm Trio) in a gallon of Distilled Water. When mixing it according to Fox Farms Feeding Schedule , the PPM in the gallon normally comes out to over 2250 PPM. I then add water soluable Cal-Mag (Non-Nitrate) from Dutch Science, which by itself in distilled water at 1/4 tsp per Gallon is 430 PPM. So , I end up with a PPM around 2650 on average. I then take an empty gallon jug and I Mix my nutrient solution with plain Distilled water u til I get a reading of around 1000-1100 PPM. I then top water my plants. The next watering, I will only feed water and Cal-Mag, which is 430PPM. I top water and then I check the runoff PPM which comes out to around 1000-1100 PPM. So I deduct the 430 PPM I just watered with to get the runoff, which comes out to around 680 PPM, meaning that the plant had used up around 430 PPM since the last feeding? Am I doing this wrong, should I not deduct the current PPM of the water. Should I proceed with upping the PPM by 400, because it's using it up between feedings , so that way by the next feeding it will still maintain around 1,050 PPM? Sent from my SM-F916U using Grasscity Forum mobile app
take your gallon of distilled water then add your cal mag i stick with 2.5 mil max on the stuff myself check your ppm then take your trio and forget what they tell you to use, use 1/4 strength after you have done that check your ppm again . if it is too high for stage of plants, just add more water to dilute it if it is not enough it really depends on the stage of your plants for what you do, in veg the grow big would be my plan of action, add 1 ml at a time to change the ppm you need i asume your growing in soil , if you are dont worry about your runoff ppm unless you have issues here is a tip igive folks on the trio nutes or any nutes, take 3 glasses fill all three glass with 1 cup of distilled or ro water , check and document ppm then in each glass put 1 mill of each bottle and check ppm if you know what 1 mil of your nute is when singled out, you therefore know which one to use when your trying to get your water ideal for what you need , if you can see the plant might need a little more nitrogen well you know which one to use by the macro numbers on the bottle, it been a minute since i used the trio , but one of them has more nitrogen, i dont use that one as much during flower, , green is all good but it hard as heck to flush in the end game