First time grower, need a little help

[beepboopboopbeepbop]

Some details:
Day 40 since germination
soil: foxfarms happy frog on top, foxfarms strawberry fields on bottom
lights: 2x HLG 100 V2 - RSpec in a 2x4ft tent
nutes: foxfarm big bloom, grow big, tiger bloom

plants: 2x jean-o Blueberry Cheezecake, 2x fast buds fastberry

All 4 plants have been growing pretty different as seen in the picture, leftmost and rightmost are the cheezecakes and middle are the fastberry.
Once buds started showing, I brought the lights down closer to about 18" as per the spec sheets for the lights, the fastberries leaves started to change as in the picture, the past week I pulled the lights back to 24" thinking it might be light burn.

Last feed was just water 7.0 pH, runoff ~5.4-5.6 pH. Previous feed: big bloom 2tsp, grow big 1tsp, tiger bloom 1 tsp adjusted to 6.8 pH

I'm concerned that i have a mix of light burn and nute burn and low pH. Some of the leaves are crunchy and some are just spotty.
Should I try to pull the pH up harder? Adjust the water to 8.0 pH and flush? I haven't used any other nutes other than the above.

temp is around 77F, RH is around 60%

 

[Bill.de.Cat]

Start at the begining...where does your water come from....city tap, well tap, distilled, RO? I ask because my well water is super high in calcium etc. ( limestone aquifer) and gave me no end of problems till MoG zero'd in on calcium causing lock out of other nutrients........I know the net has all kinds of pH levels, I've found 6.0 to 6.5 to work best for me using HF only, last's into flowering then I start in on the nutrients. Others more knowledgeable can most likely give you a good dianosis .

 

[beepboopboopbeepbop]

Water is potable city water, pH ~7.0
I keep finding it strange that my runoff is so acidic, and the plants all behave different even though they get fed the same/use the same soil.
I've been using the mentioned nutes throughout the grow, although at less frequency and strength as the feeding schedule said to avoid burn (although trying to keep the same ratio).

 

[DCLXVI]

Happy frog is potting soil, the Strawberry fields is coco based. Soil and coco need different things. Might be part of the issue. I suspect there is more than 1 issue going on. Both of those "soils" have nutrients in them. Could be too much fertilizer overall.

I'd run some plain water for a few sessions, try a bit lower on the pH and see if things don't straighten out. Runoff pH isn't a good measure. You could do a soil slurry test. Scoop out some material from as low down as you can get in the pot without disturbing things too much. Mix equal parts soil/distilled water and then gently insert your pH probe. It should be a loose slurry. If you need a little more water that is ok. That will tell you more closely the actual soil pH.

Soil can be run from 6.0-7.0pH but coco ideally is 5.8-6.2pH, since you've combined both in one pot, I would try watering around 6.2-6.3 and see if that doesn't help things out a bit.

 

[Bill.de.Cat]

Water is potable city water, pH ~7.0
I keep finding it strange that my runoff is so acidic, and the plants all behave different even though they get fed the same/use the same soil.
I've been using the mentioned nutes throughout the grow, although at less frequency and strength as the feeding schedule said to avoid burn (although trying to keep the same ratio).

OK, city tap....do you let it breathe for 24 hrs before adding nutrients?....If they use chlorine for sterilization sitting for 24 hours usually disapates it...if the use chloramines then you should switch to distilled or RO water.
From the web: Chloramine is a combination of ammonia with chlorine. The ammonia binds the chlorine gas to keep it in solution longer. Unlike straight chlorine, which dissipates fairly quickly when exposed to air, chloramine remains in the water longer. That's good for the water company tasked with keeping public drinking water safe from contaminants such as bacteria. It's not so good for those of us who keep fish and want to use our tap water to fill the aquarium.
added..........Or plants

 

[beepboopboopbeepbop]

Happy frog is potting soil, the Strawberry fields is coco based. Soil and coco need different things. Might be part of the issue. I suspect there is more than 1 issue going on. Both of those "soils" have nutrients in them. Could be too much fertilizer overall.

I'd run some plain water for a few sessions, try a bit lower on the pH and see if things don't straighten out. Runoff pH isn't a good measure. You could do a soil slurry test. Scoop out some material from as low down as you can get in the pot without disturbing things too much. Mix equal parts soil/distilled water and then gently insert your pH probe. It should be a loose slurry. If you need a little more water that is ok. That will tell you more closely the actual soil pH.

Soil can be run from 6.0-7.0pH but coco ideally is 5.8-6.2pH, since you've combined both in one pot, I would try watering around 6.2-6.3 and see if that doesn't help things out a bit.

Sounds like I messed up with the growing medium.
I don't understand trying a lower pH though, as the runoff is currently around 5.4, wouldn't a lower pH affect the plants? I've been trying to pull the pH up for the past few feedings, as I was assuming my issues have been due to low pH.
I'm also confused why all 4 plants look so different as they all have the same growing medium as well as been on the same feeding.

 

[DCLXVI]

It's ok, you can make it to the end! First grow, plenty to learn. Don't fret.

Do the slurry test first and see where your soil pH is sitting. The runoff isn't accurate, most likely it is carrying a lot of fertilizer causing the low pH number. The StrawberryFields has dolomite lime in it which should help buffer the pH in that layer. The runoff will contain a lof of the fertilzer you are washing out of the pot, which is typically quite acidic. You can test the input EC and runoff EC.

Most of the time, you can test for runoff pH to gauge fertilizer building up in the soil, which causes it to get very acidic as well. Measuring the input and runoff EC is a much better way to tell. If the runoff has a higher EC than the input, you have fertilizer buildup. Check the runoff pH to see how bad it is and if you need to do anything about it.

The availability of nutrients depends a lot on the pH of the solution you are pouring into your plant. Coco likes a bit lower than soil and there is a good range for soil that just overlaps the coco.

I suspect there is too much nutrients in there overall.

Start here:
1) slurry test
2) EC/ppm and pH of your nutrient/water mix
3) EC/ppm and pH of your runoff

 

[beepboopboopbeepbop]

I don't have a TDS meter currently.
Slurry = 6.8 pH
Tap = 7.5 pH
Runoff today was 4.9 pH

If you think there might be too many nutrients in there, should I continue watering until runoff every time the top soil dries, or force it every 2 days even if?

 

[DCLXVI]

Perfect! As you can see the actual soil pH isn't looking too bad at all is it? Just that runoff!

I would only water when it needs it just as you have been but a nice full soak. Water, water, water, light feed, then 3x watering again. The leaves that are damaged won't recover but you can probably limp it to the finish. They aren't looking too bad overall.

I'd go half strength on the feed and maybe try watering at varying pH 6.3, 6.5, and 6.8 as you have been. Try that for a couple weeks and check that runoff pH, see if it moves. Good luck!

I know when you first start out it can seem like there is always something else you have to buy. I would highly recommend investing in a TDS/EC/ppm meter when you are able. I have an HM Digital Com-80, they run right around $25. You don't need storage solution but I highly recommend their calibration fluid. It makes it much easier to mix and adjust nutrients when you know the actual number instead of the approximate 1tsp 2tbl 1/2ml etc...

Amazon product

 

[MIAutomatic]

It’s definitely an issue related to excess something, possibly multiple things. It could be related to your feeding, water source or both. Get an EC meter ASAP, getting a cheapie is probably ok for now but upgrade when you can and make sure to keep it calibrated. The fact that your runoff PH keeps dropping is a good indicator that you probably have high EC.

You could do a soil slurry, it will be more accurate, but runoff EC and PH will still give you a pretty good idea and is much easier to collect and test. If you are unsure of your water quality you can also pick up some RO from the supermarket and buffer it with a little bit of calmag (about .2 EC or 100 ppm) until you get your long term water situation sorted out.

My guess is if you start watering with slight runoff with some good clean buffered water that after 2-3 waterings things will start looking better. The combination of the dark green leaves mixed with the necrotic crispy leaves is the other sign of overfeeding or high EC water source that leads me to suggest this course of action.

good luck!