Calcium deficiency and nitrogen lock out? Flush?

GnomishViking · Aug 14, 2025

Needing a little help with my indoor grow. Up until a week ago this was a very healthy looking plant and is currently finishing up week 6 of flower, has about tell second week September to go. The plant is grown in HP pro mix and I do a feed water feed schedule with my liquid nutes and I feed and water with a ph between 6.1-6.4. PPFD has been between 700-800. I gave cal mag the last time I watered a couple days ago, but it keeps getting worse. The fan leaves where very dark green and clawing downwards, so I assumed I over fed the plant and now it is having lock out issues.

My main questions, is if I give it a flush this late in flower will that cause issues, or should I just lower my feeding and ride this out?

Suds.an.buds · Aug 14, 2025

What light you running and how high from your canopy?

GnomishViking · Aug 14, 2025

Suds.an.buds said:
What light you running and how high from your canopy?

SpiderFarmer sf2000. Have it at 80% and about 20 inches away, which is farther away and less power than it recommends at this stage.

MileHiGhost · Aug 14, 2025

It that hydro? Or soil. Can't tell from pic's.

Ninjadogma · Aug 14, 2025

I would just keep pushing it exactly like you have, they don't really look that unhappy. Maybe check your runoff pH and if it's below 6.0, adjust it upward to get there. That should help improve calcium uptake.

If you're considering flushing, stick an EC pen in your runoff and see if it's even necessary. If it's not high pm or EC, I'd leave it be. Personally not a fan of depriving a plant of nutrients just because someone on the internet told me it will taste better.

Ninjadogma · Aug 14, 2025

MileHiGhost said:
It that hydro? Or soil. Can't tell from pic's.

HP Pro Mix = nuteless medium

Suds.an.buds · Aug 14, 2025

GnomishViking said:
SpiderFarmer sf2000. Have it at 80% and about 20 inches away, which is farther away and less power than it recommends at this stage.

Im no pro but i would raise the light up and maybe dial back a lil my last 2 runs i over did with light and they we’re looking similar but i seem to stop it on my current by backing off my light definitely wait for more experienced growers tho

Suds.an.buds · Aug 14, 2025

Ninjadogma said:
I would just keep pushing it exactly like you have, they don't really look that unhappy. Maybe check your runoff pH and if it's below 6.0, adjust it upward to get there. That should help improve calcium uptake.

If you're considering flushing, stick an EC pen in your runoff and see if it's even necessary. If it's not high pm or EC, I'd leave it be. Personally not a fan of depriving a plant of nutrients just because someone on the internet told me it will taste better.

To me it seams like the leaf tips are shying away from the light but like i said i only have a few grows under my belt and always causing my own issues but how else can you learn right

MileHiGhost · Aug 14, 2025

Ninjadogma said:
HP Pro Mix = nuteless medium

I do DWC, when I see any issue I dump flush, if it's like a coco type medium that doesn't retain nutrients you should be able to flush rather quickly. If your medium retains nutrients I had to flush for a week. That did slow down growth.

GnomishViking · Aug 14, 2025

MileHiGhost said:
It that hydro? Or soil. Can't tell from pic's.

My post mentions its grown in HP promix

GnomishViking · Aug 14, 2025

Suds.an.buds said:
Im no pro but i would raise the light up and maybe dial back a lil my last 2 runs i over did with light and they we’re looking similar but i seem to stop it on my current by backing off my light definitely wait for more experienced growers tho

I am having issues lower down on ht plant now too, so I dont think it's the light. It's pretty dialled back as far as PPFD goes.

GnomishViking · Aug 14, 2025

Ninjadogma said:
I would just keep pushing it exactly like you have, they don't really look that unhappy. Maybe check your runoff pH and if it's below 6.0, adjust it upward to get there. That should help improve calcium uptake.

If you're considering flushing, stick an EC pen in your runoff and see if it's even necessary. If it's not high pm or EC, I'd leave it be. Personally not a fan of depriving a plant of nutrients just because someone on the internet told me it will taste better.

I actually never have gotten run off this grow. I put in 1gal into the 5 gal pot and while it is very saturated, none comes out the bottom. Which is odd, cause previous goes in the same medium has given me run off.

Phil.D. · Aug 15, 2025

I think it’s a calcium deficiency too. I had it on a Dosido Auto this spring and I treated it with gypsum. I tsp/gallon. (I ground it fine in a spice grinder). The plant responded almost immediately. When I was hunting around trying to fix it, I saw where a guy contacted buildasoil and BAS sent him the fix. That is what I did.

Then watch the new growth carefully for symptoms.

Calcium deficiency and nitrogen lock out? Flush?

Calcium deficiency and nitrogen lock out? Flush?

GnomishViking

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