What is this on my autoflowers leaves?

I have two auto flowers and they have this weird spots on the leaves and the leaves tips are hard and brittle. The plants are in 2 gallon smart pots with fox farm happy frog soil with 25% added perlite. They are under a 300watt mars hydro led (132 actual watt) in a grow tent. I have been watering them with just plain ph’d water (6.2-6.5ph). The strains are short stuff big gun and royal Queen quick one. I can’t figure out what’s wrong with them, they were growing really well and haven’t been growing as much.The plants are almost into week 4 and just started to flower. What do you think is the problem with them?

Tap water or RO?

Is the soil to "hot" for 'em?

Something is too hot. Soil since just plain water used. Miracle Gro? Kelloggs?

hotrodharley said:

Something is too hot. Soil since just plain water used. Miracle Gro? Kelloggs?

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Definitely seems so

I was using tap water but I let it sit for a 48 hours to let the Chlorine evaporator, the soil is fox farm happy frog with perlite added and I’ve been just using tap water with a ph of 6.2-6.5 .

That's odd then, I've run autos in FFOF with tap water that's been in my res for at least 48hrs (my res has airstones going in it though too so that helps) without an issue. But my point is from what I gather FFOF is hotter than FFHF, I'd reckon that I'd be more likely to encounter this problem than you I'd think.

What strain is that your running brother?

The bigger plant is short stuff big gun and the small plant is royal Queen quick one both are feminized autos

Jacksolof said:

The bigger plant is short stuff big gun and the small plant is royal Queen quick one both are feminized autos

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I haven't run those before but i'll be watching.

It definitely seems like it's a hot soil situation from the looks of it.

What can I do to fix it or make it better?

did they veg at all? maybe you hit them with a lot of PK?

Looks like the veg got fudged due to over feeding this is a bag seed autoflower at day 28 with 120 watts and 1 gal of soil. Organic.

They did veg but the bigger plant was growing really well then just stopped and the smaller one never grew well. Maybe the seeds I got for the one royal Queen we’re messed up. I didn’t feed them at all just used plain ph’d water for them