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Hydroponic Tomatoes have yellowing leaves

Posted by speckledapple Wisconsin (My Page) on
Thu, Apr 11, 13 at 20:51

I planted some tomato plants on 3/5/2013.

Seed Type: Super Sweet 100 Hybrid Tomatoes

Water PH: between 5.8 and 6.5

Light Source: 2 - T8 Skylight bulbs

Room Temp: Day 70F Night: 60F

Fan: Open windows provides plenty of air in the room. No fan blowing directly on area

Medium: Coconut coir disks

Setup: 5 gallon gray container

Water Source: tap but ph’ed down to get the right ph for garden

Nutrients: david’s grow (grow, base) with MagCal and Fulvic acid added midway through the cycle timeframe (as I was worried about nutrient loss)

Airstone: one giant one


As seen in the photos, the leaves are quite yellow with no real reason as to why. Initially when I saw the leaves yellowing I cut off the most yellowed leaves, replaced the nutrient solution and added the fulvic acid and magcal. I also got a light (grolux) that I thought was great for the plants. Today I replaced the grolux with bright t8 skylight bulbs (the closest to sunlight I could find). The stems are purple. Since this is my first time I think maybe it was that I placed too many tomato plants close together (3 essentially very close in one net pot) but with the yellowing it could be some virus also. Any suggestions on where I can grow from here would be great. Thanks.

Follow-Up Postings:

RE: Hydroponic Tomatoes have yellowing leaves

Purple stems could be a potassium deficiency. The yellowing looks like an iron deficiency.
Make sure your nutrient contains the deficient nutrients.
Also, make sure the concentration is strong enough.

RE: Hydroponic Tomatoes have yellowing leaves

New growth that appears yellow is sometimes a nitrogen deficiency. Is "David's Grow" a soil nutrient mix or hydroponics?

RE: Hydroponic Tomatoes have yellowing leaves

you think it could be the light? david's grow is purely hydroponic nutrient mix.

RE: Hydroponic Tomatoes have yellowing leaves

The plants aren't "leggy" so light is not the issue.

RE: Hydroponic Tomatoes have yellowing leaves

what can I do to remedy the lack of nitrogen? davids grow seems to have a substantial amount.

RE: Hydroponic Tomatoes have yellowing leaves

Well, the only way would be to add more fertilizer to the reservoir. Do you have a way to measure the EC/ppm of your solution?

RE: Hydroponic Tomatoes have yellowing leaves

Not at the moment but since it is only a 5 gallon bucket, I am thinking of scraping the plants as they look pretty damaged and just start more but this time with the right mix of fertilizer.

RE: Hydroponic Tomatoes have yellowing leaves

The plants will recover in a few days, just give more fertilizer/nutrients and give them a chance. Tomatoes are tough and can take some abuse. Add more nutrients and see what happens.

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