Correct PH Level - Soil grow in Cloth Pots

The set up is soil (blend of FFOF and FFHF) in 5 gallon cloth pot that is sitting in a 16"dia x 3"deep tray to catch runoff and feed back.

I’m using GH Flora nutes, 1/2tsp per gallon of each, and feeding a gallon at a time. I PH the batch down to 5.8-6.0 before feeding (my tap water is around 7-8). When I checked the runoff water in the tray, it’s low. Like down around 5.0-5.5.

I don’t know how it can possibly be that low, considering the soil mix and the nutes I’m using, but I’ve checked it several times and get the same (low) results.

The way I understand these cloth pots work, they soak that liquid back up into the soil as the plant needs it. I’m worried that if it’s soaking up that low PH water, it’s going to hurt the plant in the long run. Is it okay for me to keep going like this as long as my feeding PH is correct?


For soil you should be ph’ing your mix to 6.5 not 5.8, as far as I understand thats the ph you want for hydro and soilless mediums. To fix the low ph i would ph your water to 6.5 and flush with just that water at a rate of 2-3x the volume of the pot.
Also, I had problems using trays to catch my runoff. Yes it does save nutrients and feed them back up but any toxins in your soil are not getting flushed out, just sucked right back into the soil. I think it is worth watering them more often without the tray underneath than saving water with the tray and potentially causing damage.
Whats the ph of your nutrient/water solution you feed them with?

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Thanks @BondPacker
The 5.8ph is the complete nutrient solution I’m feeding. I mix up a batch, let it sit for a few mins, then check pH and ppm. It usually ends up around 8.0 and I have to adjust down. Also, I was in fact going off the same levels I am using for hydro. Didn’t know I needed it to be higher for soil, but now that you mention it that makes sense.

This is a first time grow for me, with both my hydro setup and using cloth pots. I only have one plant in a pot and was figuring on watering with 1 gal of solution, once a week. If I remove the tray and allow the runoff to drain away, is that enough feeding or should I increase?

Thats a high solution! My tap water ph is around 7.5 but when i mix nutrients in and let sit it usually comes down to about 4.5-5.5 so i have to do the opposite and raise ph. Was using bicarb soda but ordered some potassium carbonate as thats basically what they use in PH UP.

Once you remove the tray underneath it will allow your pot to dry out faster which is actually a good thing. You want to soak your soil to the point of runoff, and then let it dry out till its almost bone dry but not quite, and then soak once more. I would recommend using nutrients every time you water them but some people like to feed them with nutrients one water, and then just straight water the next etc…But as long as your not getting signs of nutrient burn, and your ph is between 6-6.5, i would use nutrients with every water.

If your only watering once a week then either your plant is young and yet to grow its roots out and fill up the pot to soak up the water(which is fine, just use less water until the plant grows and requires more), or the feeding tray underneath is holding water for too long.

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