Questions on PPM's

Here’s a chart that I use as a guide. I let my PPM come down to the levels in the chart then I maintain them at that. The soil is fully loaded right now and your plant doesn’t need anymore. Wait until it comes down to the desired level and as it starts to drop below you just mix your nutes to bring it back up. So say your PPM should be 1000, you’ve just checked your runoff and you’re sitting at 450. You need to bring it back up to 1000 by mixing a feed that equals 550. You need to check your water PPM level as well as it all adds up. Next time will be a water and so on :sunglasses:

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Okay great thanks for the chart! What do the numbers on the right represent? Also I’m getting an RO filter installed on Wednesday so that should take care of having hard water and I will be in control of all the nutes I add! Although since RO is void of all nutes should I be adding Cal-mag every watering/ every other watering? I read on Royal Queen Seeds website that it can actually strip calcium in the soil away!

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Use the chart below for conversion. The numbers on the left are ec/tds values. Bluelab use the value on the right and your Apera among others use the values on the left. One scale is American the other European. I use calmag as I’m growing under led. Never had a calmag issue when I used HiD. You could do one of two things with the calmag. Leave it out and watch for deficiencies or add it as a “just in case” not sure the best answer for you there. As for calmag removing calcium, sounds unlikely but might be possible, can’t see it though :thinking:

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You don’t want to give them that in actual nutes. Nutes from soil is different. Not all those ppms are immediately available. It takes time for the microbes to break down the elements in the soil to make them available for plant uptake. Surprised yours are only 1300 ppm. New ocean forest has been around 3000 ppm for me.

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