Damping off problems

[Adam Kimball Bevan]

Hi All. Greetings from Ohio! I'm new to the forum, and this is the first system I've had since 1999. I have a gravel media, flood and drain system located under grow lights in my garage. I am using a continuous flow pump with a bell siphon, and my system is fully cycled with 10 largemouth bass fingerlings. My typical test results are as follows:

 

Temp: 75 F

pH: 7.6 (I have some limestone in my gravel source)

Ammonia: 0

Nitrite: 0

Nitrate: ~80ppm

 

While my more mature transplants are doing well, my lettuce and cuke seedlings (directly sewn into the gravel) died after sprouting. I think it's root rot. (?) I've attached some pics below. If that is indeed the issue, how do I get rid of the mold that may be causing it without tearing out my (currently) healthy plants? Is drying out the top layer sufficient? Here are the steps I've taken so far:

 

- Lowered the maximum height of my flood to two inches below the surface (vs only ~1 inch)

- decreased the rate of flow to the bed so cycle lasts ~11 minutes (2 min drain, 9 min fill, vs ~6 minute total)

- added a small fan directed over the bed since it's in my poorly ventilated garage

 

I've also added my first capful of Maxicrop just in case it was nutrient-related.

 

I'd love to hear of good ways people have gotten rid of rot-causing mold. I've seen a couple discussions regarding Neem and Dipel working with powdery mildew - any experience using them to prevent future damping off?

 

Thank you all! I'm very glad I found such a great forum full of fun, knowledgable aquapons!

[Ken Pilarczyk]

Hi Adam,

When I direct seed in my beds, I use a a watering can until the plants are 2 - 3 inches high. I try to keep the water level 2-3 in. below the surface. Cycle time is about 20 min.

It looks like the light level may not be high enough.

KenP

[TCLynx]

I expect more light will help as will the air flow from the fan.

 

I've heard that you can battle damping off with seedlings by spraying daily with cooled dilute chamomile tea.  You have to spray before the plant damps off since once it falls over it's too late.

[Adam Kimball Bevan]

Fantastic! Thanks so much for the help. I'll use the watering can and chamomile tea when I try sowing again in a few more days. I'll report back how it goes.

[TCLynx]

Actually I think using a spray bottle with the chamomile tea is what you are supposed to do, daily until the second set of leaves are developed and damping off danger is past.

[Adam Kimball Bevan]

Of course. I meant use a watering can like Ken for periodic watering before the roots are long enough to get sufficient moisture below the surface, and a spray bottle for the chamomile. Speaking of, Ken, how often would you water the seeds when you directly sow into your beds?

[Curtis Lewis]

Hello All, quick question... When spraying with Chamomile tea, do I spray the roots or the plant itself?? Forgive me I'm a newbie... Lol.

Adam Kimball Bevan said:

Of course. I meant use a watering can like Ken for periodic watering before the roots are long enough to get sufficient moisture below the surface, and a spray bottle for the chamomile. Speaking of, Ken, how often would you water the seeds when you directly sow into your beds?