What do my plants need?!


#1

Hi Everyone, I have been growing a few pepper plants and an herb in my homemade aeroponics system for a couple weeks now and I’m told my plants look wilted. One plant looks wilted, two look alright (to me), although one had some flowers that fell off, the herb looks like part of the plant isn’t doing so good.
pictures are in the album below

I have 100 watts of LED light strips for all the plants, about 3 feet above them, I am watering for 5 seconds every 3 minutes right now using tefen nozzles @ 80psi, and the PH is around 5.9, using general hydroponics nutrients. Too much water? Too little? Too little light? I’m in the process of adding a sensor to track the moisture in the plant roots right now to try to figure this out also. Thanks in advance.


#2

This is pure guess, but I suspect the lights. Lights 3 ft from the plants is a long distance, and without knowing how long you light strip is, it is impossible to calculate the actual amount of light you have at a plant. And it is not clear if you have reflectors or the plants are out in the open.
Take a look at the MVP design (https://forum.openag.media.mit.edu/t/300-food-computer-mvp), where there are four 100w lights for an 18x24 area and the lights are 6 to 8 inches above the plants.
First try lowering your lights so they are inches above the plants.
Also check you lights, what some vendors say their lights produce can be quite different than actual values (especially with cheap imported bulbs). Get a meter and check the light at the level of the plants. Even a phone app is better than nothing. It may not be accurate, but it will give you a relative measurement to start comparing things against. For full diagnosis, nothing is as good as a PAR value and full spectrum analysis.
Also, what are you doing to pollinate the peppers? https://homeguides.sfgate.com/pollinate-bell-pepper-38916.html


#3

Ok thank you, I will try lowering the lights. I have another strip on the way. They are currently two 8ft long strips going across the top and down the sides ( the enclosure is 4ft long) and one 4ft strip going accross on a side wall about halfway up the enclosure. No reflectors right now but the enclosure is white so it reflects a bit.


#4

While lights are typically a big problem, looking at the veins on leaves and the flower abortion it sounds like you may have nutrient deficiencie(s) as well.

  1. Can you post another pic of the plants leaves? It’s really helpful to see how things change…
  2. What’s your nutrient formula? @Atom has posted loads of recommendations and specific formula’s for Tomatoes on these forums.
  3. Can you post a pic of your whole system with lights as well a link to where you got them?

#5

A little more information about the system would be helpful :wink: The plants appear to be ex-soil and with being in the aero for a few weeks i`d expect to see a bunch of new white root growth. The roots dont look too healthy so I would start with the nutrient strength and root chamber temperature. The mist timing seems reasonable but without knowing the chamber size, nozzle number and layout its hard to be sure :wink:


#6

Hi guys, thanks for the replies. I will get back to you with pictures as soon as I get home from work. You guys mentioned nutrients, right now I am using this kit, using their recommendation for aggressive growth https://www.amazon.com/General-Hydroponics-GLCMBX0003-Florabloom-Floramicro/dp/B077DCV9Z5/ref=mp_s_a_1_3?ie=UTF8&qid=1532519537&sr=8-3&pi=AC_SX236_SY340_FMwebp_QL65&keywords=general+hydroponics&dpPl=1&dpID=51w%2BbyehczL&ref=plSrch

I just read that hard water can negatively affect nutrient uptake, I have pretty hard well water, could that be it? I’m going to switch to a new mixture tonight with distilled water.

I will get back to you on the nozzles as well, can’t seem to find the link right now.


#7

Aggressive growth sounds like itll be pretty strong, i would cut it back by half at least until you see some fresh root growth. I would say the issue is related to the root environment, most likely chamber temperature and/or mist coverage. Overmisting will create hydro roots and as you dont have those iwould be leaning towards undermisting and/or lack of even mist coverage possibly coupled with high root chamber temperatures, compounded further by the high nutrient strength. The dried up leaves in one of the pics could also suggest low humidity/arid conditions in the growing area which would increase the plants demand for water.


#8

Thanks for the reply! I don’t think low humidity is a problem but the roots are probably warmer than they should be I will definitely cut back on nutrients and increase watering frequency. That said, I just noticed that 2 tomato plants that I put in just last week have new roots! The pepper plants still seem to lack many new roots, do they like the same conditions? Maybe I didn’t clean the pepper plant roots well enough before I put it in the aeroponic setup?


#9

Hi
New roots are a good sign :wink: Uprooting soil plants and placing them in a radically different environment will always cause a delay due to the stress. Toms grow faster than peppers and can take more abuse, peppers are more finicky and hate having their roots disturbed. You will find the tom plants will mostly opt to grow new roots rather than adapt the old soil roots over to aero. The peppers are slower growing so they will likely do a little of each. In the case of the toms if push the stem down below the collar you will get extra root growth from the stem which can save a little time… The ideal root chamber temp is 68F-72F but its not always easy to acheive. Prolonged root temperatures over 75F are very risky and anything over 80F will usually result in a rapid downward spiral for root health. With regards to nutrients toms and peppers are compatible in the early growth stages but have different requirements in later growth. I dont use commercial nutrients, i make my own from scratch but with the gh flora i`d recommend using a 1-1-1 ratio of grow, bloom and micro to make a solution around EC 0.5 which i guess could be around 3ml per gallon. Its best to err on the side of caution until the plants get back upto speed in the root department, If you are running drain to waste you can compare the inlet and run off ppms which will tell you if the nutrient is too strong or too weak so you can make adjustments and see the result in the runoff in an hour or so… With a recirculating system the reservoir ppm will alter very slowly.and is in a constant state of change as the runoff mixes back in. The elemental makeup of a recirculating reservoir is unknown after its been through the system.The elemental makeup of a drain to waste reservoir doesnt alter over the life of the reservoir (full to empty) because nothing comes back.


#10

Ok thank you, I will post back with results in a week or so. Thanks again.