AQUAPONIC LETTUCE

[Jack Rife]

I AM UNABLE TO GROW OUT LETTUCE IN MY SYSTEM.  START OUT AND QUITS WHEN ABOUT 2-3 IN HIGH. WATER TEMP 65-70,  PH AROUND 6.8 

[Rob Nash]

what is your nitrate level? are you planting in a seed tray with too much water in it?
the most common mistake ive seen with seedlings is too much water..

[Harold Sukhbir]

Hi Jack,

Looks like the duckweed's sucking most of your nutrient with little left over for the lettuce.

[Jack Rife]

Lettuce is planted in DWC and the nitrate is in the 60 to80 range, I have no duck weed

[Jack Rife]

have other plants ie: cabbage, tomatoes, chives & brussel sprouts

[Harold Sukhbir]

Hi Jack,

Sorry about the misconception. I saw a discussion here:

Reply by Jack Rife on October 7, 2013 at 7:22pm

I HAVE A CHOP SYSTEM AND USE THE SUMP TANK TO RAISE MORE DUCK WEED THAN I NEED FOR 30 FISH. I FREEZE THE OVERAGE IN ICE TRAYS FOR WINTER USE. DROP THE FISH TANK AND RAFT BED DRAIN LINES INTO A BUCKET WITH HOLES AROUND THE BOTTOM,  THIS STOPS MOVEMENT OF THE WATER. DUCK WEED LIKES QUIET WATER.

In

Duckweed problems

[Jack Rife]

I HAVE A CHOP SYSTEM AND USE THE SUMP TANK TO RAISE MORE DUCK WEED THAN I NEED FOR 30 FISH. I FREEZE THE OVERAGE IN ICE TRAYS FOR WINTER USE. DROP THE FISH TANK AND RAFT BED DRAIN LINES INTO A BUCKET WITH HOLES AROUND THE BOTTOM,  THIS STOPS MOVEMENT OF THE WATER. DUCK WEED LIKES QUIET WATER.

In

Duckweed problems

[Alex Veidel]

Lol, I had wondered where you were getting duckweed....I thought maybe you were checking the profile pages for extra info :)

Harold Sukhbir said:

Hi Jack,

Sorry about the misconception. I saw a discussion here:

Reply by Jack Rife on October 7, 2013 at 7:22pm

I HAVE A CHOP SYSTEM AND USE THE SUMP TANK TO RAISE MORE DUCK WEED THAN I NEED FOR 30 FISH. I FREEZE THE OVERAGE IN ICE TRAYS FOR WINTER USE. DROP THE FISH TANK AND RAFT BED DRAIN LINES INTO A BUCKET WITH HOLES AROUND THE BOTTOM,  THIS STOPS MOVEMENT OF THE WATER. DUCK WEED LIKES QUIET WATER.

In

Duckweed problems

[Jack Rife]

I HAVE A CHOP SYSTEM AND USE THE SUMP TANK TO RAISE MORE DUCK WEED THAN I NEED FOR 30 FISH. I FREEZE THE OVERAGE IN ICE TRAYS FOR WINTER USE. DROP THE FISH TANK AND RAFT BED DRAIN LINES INTO A BUCKET WITH HOLES AROUND THE BOTTOM,  THIS STOPS MOVEMENT OF THE WATER. DUCK WEED LIKES QUIET WATER.

In

Duckweed problems

[David - WI]

Lettuce (supposedly) won't tolerate salt; so if you're using any salt for your fish that could be a problem?

Also, humidity for Hernando, Fl showed 29% one day when I looked and near 0% today... lettuce needs 60 - 80% RH to grow well (according to Dr. Resch: Click).  You might need a greenhouse or some other covering to hold in some moisture?

[Jack Rife]

Duck weed is gone, system is in a greenhouse and the humidity has been in the 50s, No added salt.  I have lettuce in another greenhouse in a hydroponic system and growing like crazy.

[Harold Sukhbir]

Hi Jack,

The most information you can give about your particular system would be the best to do here . Type of Fish feed, flowrates, system ratios, all water readings, description of root system over the period, any photos and anything else you can come up with.

[Jack Rife]

Thanks for the come back I have 30/ 2lb tilapia in 250 gal tank, 100gal sump tank 210 gal DWC tank 8 in deep, 3/ 42 X42 in grow beds, 30gal swirl tank filter, with a 600 gph pump. Roots are about 10 in long and clean, I think they should be longer' Thought I had some pictures but unable to find them, will take and fwd. pictures and water tests tomorrow. 

[Jack Rife]

Harold here are pictures of my system. The lettuce was added to the sys 2 mos ago.

[Harold Sukhbir]

Hi Jack,

I'm guessing that your water readings are Ok. Your flowrates are good. I see your fish ratios are high( almost double), so are you feeding smaller amounts? Your temps are a bit on the low side as you know. The two concerns I see are the low temps(slows growth) and possibly a low input of nutrient(also slows growth). The low temps may diminish your bacterial colony as well and reduce nutrient conversion somewhat. The root length, for lettuce at this stage are good. Also, the 8 inch DWC height is not optimal for fast growth. BTW, nice set up you have there!