Calcium deficiency or PH

I am starting a new grow, and the plants are about 3.5 weeks old.

My setup is

1 gallon pots
Happy frog soil
RO water
Fishsh&t for microbes

I haven’t started feeding them yet other than phd water with fishsh&t and ph’d to 6.5. For the first couple of weeks I was only watering them with about 16-24 oz of water and with that amount I was not getting runoff… because of the size of the pot and smaller plants I didn’t want to soak it.

I started to see a deficiency yesterday where on one of the genetics (2 plants) , the leafs were starting to spot brown and curl on some of the large fan leafs.

I suspected calcium since I realized the watering I was doing with RO, I failed to add Calmag.

Today I watered them to 20% runoff with 1/3 dose of Jacks, a little extra Calmag and fishshit. Since this is the first time I watered to heavy runoff, I measured the PH of the runoff and it was only 4.98…. Is this typical on the first runoff coming out of the soil, or do I need to water again tonight with a higher PH water. Any recommendations would be greatly appreciated…below are some pics.


At 4.9 your plant is locked out of nutrients uptake. Since it is your very first runoff I don’t really see why the numbers would be off nonetheless you need to flush until your soil starts reading 6.5

If you’re using RO water use Cal mag and pH to 6.5

I’ve now gone into a costume when I flush I use tap water that is set for 48 hours at room temperature. My tap water has a high PPM like 375ppm and I simply paid it and flush it.

Once you get a runoff of 6.5 pH you’re good. You then want to look at the ppms you run off. In Happy frog soil do not feed until your ppms run off 900 PPM

So to recap simply ph your water to 6.5 flush until your runoff is 6.5.

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This early in grow I would probably top dress with a little bit of lime and lightly mix into top of soil. The more fine the lime the faster you will see results, but it will still take a couple of weeks. For the time being running extra ph’d water through will help.

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Ph, iv seen it a lot. Idk why it keeps happening. Give her a Good drench in nutrient solution at 6.8ph. This should hopefully get the Ph to (stick) a little higher.