Optimizing water quality (PPM and PH)

 I'm growing ak-47 and bubblegum in fox farm ocean forest soil using 2 gallon smart pots (transplant to 5 gallon later on) they're about a couple days shy of a month from germination. I've been using RO water with a zero ppm and the runoff is 180 according to my honeforest TDS meter with a 6.5 PH. I'm growing indoors in a 4x4x6.5 tent with two190cfm inline fans (4 inch) with carbon filters and no added co2. I've got a Optic 4xl lighting system to go with the tent. Currently I'm running a 20 on 4 off light schedule with temps ranging from 66F at night and 72F for the daytime hours. I try to keep the humidity between 45 and 60%, the humidifier I'm using isn't very consistent. 
 I'm trying to keep an optimized environment and part of that is PPM. I got the meter a couple days ago and haven't quite grasped the concept of it. Any advice/info about it will help as all I know is it means parts per million (minerals/nutrients in the water).

Going to follow this one. I’ve got a pH meter that is also a TDS (PPM) meter as well. I have no idea how to interpret or manage nutes from a TDS perspective. I just know that too little nutes is much better than too much nutes, so I under-feed my plants.


If the nutrients you are using doesn’t have a guideline, here is a basic guideline to follow

Seedlings: 100-250 (nutrients aren’t needed here, hence there’s not a lot of particles needed)

First Half of Vegging Cycle: 300-400 (this is usually after you transplant, which still doesn’t require many nutrients)

Second Half of Vegging: 450-700 (you’ll start giving your plants more nutrients at this stage)

First Half of Flowering: 750-950 (your plants will be eating more as they grow, so they’ll be taking in more nutrients)

Second Half of Flowering: 1000-1600 (this is when your plant’s eating the most, especially if you give it additives)

End of Flower, Entering Harvest: As close to 0 as possible (this is when you’ll be flushing your plants, so you don’t want there to be a lot of particles leftover)

You can always push those numbers a little higher and watch your plants. When you start seeing the tips yellow (painted nails) you know you’ve reached their max and you can back off a little


So increasing nutrients is directly related to PPM? Also if you have the max nutrients in the water and the ppm is still low/high what else could you do to lower/raise it? Thanks for the guideline

Yes, nutrients are your dissolved solids. TDS is total dissolved solids which is read in ppm (parts per million) or EC (electrical conductivity).

If you after adding nutes, your TDS is still low, you can add more. If it’s too high, pour a little of your solution out ( diluting the solution) and add more water. Shake it up and test the TDS again until you’re where you want to be.


Perfect, Thanks, screenshoted this !

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