HELP! Is somebody eating my plants, or is this a nutrient/pH issue, or what?

[QueerHobbit]

This is my third grow. Hydroponic with LEDs. I’ve got three fairly happy plants, just switched to bloom a week ago and they’re growing fast.

Two of my three plants, however, are showing some signs of unhappiness on older/lower leaves.

Tora Bora: Something that looks like somebody was chewing on the underside of a leaf near the midvein. Several leaves have pale/shiny spots between the veins on both top and bottom.

Blueberry: Tiny speckly pale green marks all over the top of the leaf. Nothing visible on the underside.

Any thoughts?

[homegrown]

Hey QueerHobbit, im not a Hydro grower but for pics 1&3 im guessing ph or root issues - https://www.growweedeasy.com/cannabi...h-fluctuations. And for pics 2&4...sure does look like bug problems. I think a closer look might be in order. Last pic looks like mite or thrip damage..dont even know if you can get thrips in a hydro set-up??

[Cloud]

You can definitely get thrips in hydro. Ive gotten them before when i washed my coco outside and spread to my DWC from there. Not hard to get rid of at the end of the cycle.

[Cloud]

I agree with homegrown you got ph issues or root issues. I dont agree with the thrips in pic 4 looks like more damage from issue stated earlier. Pic 2 though is a little suspicious so needs more investigation..

[dilvish]

inspect the plants all over and take your time looking really close. pests can go undetected if you don't thoroughly inspect.

[DW2]

Howdy QueerHobbit, What is the pH and water temperature of Your reservoirs? What nutrients are You using and the concentration?

[QueerHobbit]

dilvish I was afraid that was what I needed to do. 😝

[QueerHobbit]

DW2 My tent temp has been 68-77 F for the past couple weeks, so I assume my water is about the same. I set the pH between 5.5 and 6.5 when I do my weekly reservoir change. I think maybe I need to check it more often between reservoir changes?

I’m using the Flora trio (micro, grow, bloom). I’m not sure what the concentration is in typical terms, but it’s been…approx 5-6ml/gal total lately.

[DW2]

QueerHobbit, The water temperature should be kept between 62° F and 68° F (17° C - 21° C). Invest a couple of bucks (I have been using the Grow brand for several years now and they are around $7) for the water thermometers too be certain of the temperature. A water temperature above 70° F can lead to the brown algae to start (root rot) and that can play havoc with the plants well being. The water will be warmer than the ambient air temperature especially if there water pumps circulating the water and air pumps pushing air through the air stones (there's always friction! lol). I do not 'chase' the pH up and down because as the plants take up the nutrients from the water, the pH will change. I only set the pH of the nutrient and fill water to 6.0 pH and let it 'do it't thing'. I don't adjust the pH between feeds and top offs only if it gets way out of range. Several years back, I almost killed off some of my plants by 'over adjusting' the pH directly in the reservoir. I found that it is much safer to drain and start over new with the feed mix than to stress or even kill the plants if problems occur like algae blooms, pH imbalance, or nutrient lock out.

[QueerHobbit]

Smoklahoma That makes sense. I’ll make that part of my daily routine! And I guess that means I should start on the low end of the pH range.

[QueerHobbit]

DW2, How do you reduce the temp in your reservoirs?

I will definitely be judicious with pH adjustments. Thanks for the heads up about overdoing it. When I checked last night 1 day after a reservoir change, none of the pH levels were out of range. However, I checked pH of the old water before the reservoir change and it was ~7.0, so I’m definitely going to keep an eye out and be ready to make some adjustments.

[dilvish]

here is a guide for the GH trio https://www.growweedeasy.com/wp-cont...169.1637258913

[QueerHobbit]

Cool, I’ll compare that to my current nutrient schedule and see where I need to adjust!

[DW2]

Howdy QueerHobbit, Something that I forgot to say (71 year old neurons don't communicate well with each other! LOL!!!), the different nutrients are best taken up by the plants at varying pH levels (see attachment). Also if the pH is maintained at a relatively constant level, some problems may be difficult to diagnose, such as 'nutrient lock-out' where the plants quit taking in the nutrients (the pH level will not change as they normally do as the plants take in the nutrients, changing the pH).
Here's the nutrient/pH chart:

[Coco]

looks like thrips to me. I had them tried all the usual sprays,, gone then, oh no here they are again.. eventually used DE soil. Fingers crossed it seems to have worked. 2 grows now nothing.