I’m starting “A Salad A Day” project.  I’ll start with a lettuce station.  Comments are most welcome! I am hoping to get your feedback on what you would like to see and/or how what improvements I should make.  Better – how about you starting your own lettuce station and we compare results along the way?  


Source: Kratky Discussion, Big Plans, and Hydroponic Seedlings


The Goal

The goals of this project are to provide:

  •  100% of my daily lettuce usage.  I have a salad a day.  We also use lettuce in other meals, most notably as a hamburger topping.  
  • learn a lot about two of my passions – gardening and hardware/software.  This is where I could use your help.  I may have passion but I lack knowledge.  I am new to electronics, hydroponics – especially when it comes to nutrients.  The plants I have grown hydroponically have been at best OK, but not nearly as magnificent as I see pictures of from the hydroponics folks on the /r/hydro subreddit.  I just made my first PCB board with a tremendous boost in knowledge from Chris Gammel and his Contextual Electronics course.  

The goal of this post is to get to start the Lettuce Germination Station.

Thanks to Those that Go Before

 An extroardinary aspect of the Internet is its enablement of community learning.  Frontrunners in this community who put the love of each one of us before the love of money.  They are proving that a person can make more than a decent living while at the same time sharing what they learn as well as learn from others.  Twenty years ago, we were not as forthright with our knowledge.  This proprietary culture bent us in the direction of greed – always wanting more for ourself.  I thank all of you who passionately learn and share what you learn.  THANK YOU!

For this post I would like to thank in particular the Hydro subreddit.  Thank you to all the knowledgable folks who kindly share their experience and what they have learned.

Growth in Two Stages

I am separating the lettuce growth cycle into two stages.  

The first stage is the growth period between planting the seed and transplanting the seed into the hydroponics station.  


Stage 1: Germination

I’ll refer to this as the GERMINATION STATION.  

The second stage is growing the lettuce plant into a tasty star of my salad.


Step 2: Growing UP

 I’ll refer to this stage as the GROW STATION.

Germination Station

I’ll be able to build the germination station in less than an hour because I have all the pieces to get going.


For lighting during the first stage, I will be using the T5 setup I discussed in this post and compared its light measurements with other light setups I had at the time in this post.   It has been awhile since I purchased, but I recall the cost being around $50 at Home Depot.



mhpgardener pointed out in this youtube video that seed starts do not need the pricier LEDs.  This makes sense since the leaves are not that big and the main goal is to grow healthy roots.  


Great plants start with great seeds. 


I’ll be trying Seattle Seed Company’s Buttercrunch Lettuce seeds.  One seed pack costs $3 + tax.  For me this came to $3.29 (our sales tax is currently 9.5%).  I’m estimating there are around 50 seeds in a packet.  I’ll be planting 2 seeds at a time.  This makes the cost per planting to be $3.29/25 or $.13 per planting.

I support a local company that wants to provide a quality experience.  More and more I find myself searching out our local small businesses to put a face behind a product. Something I don’t get in the larger chains.  Also, I like the idea of supporting our local economy.  With that said, I’ll keep an eye for how many seeds actually make it to the next stage.  It will be an ongoing dance between the seeds I use as well as honing my skills in growing from seed.  I’d love to hear where you get your seeds and how well they have done for you.

I’m starting with Buttercrunch.  I plan to open our pallet to a variety of lettuce types once I have a better feel for growing a continuous crop of lettuce.

Plant Starters

There are many different materials I could use for plant starters.  For now, I’ve chosen to use Grodan’s rock wool plant starters.  A sheet of 98 costs $16.21 + sales tax.  The total comes to $17.75 or $17.75/98 $.18 per planting.


 As Grodan points out:

The most important quality a high grade Rockwool should have is uniform wetting. The Rockwool should wet easily but not remain water-soaked.

Dome House

I bought this dome awhile back at a nearby hydroponics store.  



They cost a little less than $20.  I ended up using a Jiffy starter pack enclosure I recycled that had cost me $5.  


It should be good enough.

 I also use a heat mat which I’ve had for awhile.  The heat mat adds about $20 to the cost.  The final part is a timer.  The cost was with sales tax came to $11.94.


Once the plant has cotyledons, I am going to introduce nutrients at 1/4 strength.  I am not sure 1/4 strength is the best amount. My intent is to provide the growing plant with just enough food to thrive but not too much to kill it.  How and what nutrients I use will be something that will evolve over time as I learn from both growing and what others are doing.  I had purchased pH Perfect Sensi Grow because their claim sounds too good to be true (and you know what they say – “If it sounds too good to be true, it probably IS too good to be true.”  It has also been said “A sucker is born every day.”  It wouldn’t be the first time I wear the shame of sucker if marketing claims don’t reflect reality 🙂 ).  Their claim:

If you use any pH Perfect base nutrient as directed, you will never again have to monitor and adjust your pH.

YOWZA!!  or as I like to say a YIPPEE! moment.  Since supplying my family with our lettuce needs will be chock full of learning, I will boldly start believing in this statement.  I’ll come back and compare with other nutrients and methods over time.  I paid $33.64 for 1Liter.  I haven’t thought of a good way to break down the amount of nutrient per plant.  I’m going to make a guestimate of $.05 per plant for nutrients during germination.  The cost of nutrients will be something I hope to understand better as I gain more experience.

I won’t take pH measurements, but will take nutrient (i.e.: conductivity, or EC level) measurements.   I bought this inexpensive TDS Tester for $17.07 with tax.  It seems to work pretty well.  Also, it seemed that several on the hydro subreddit used this tester with success.


I do not have an accurate measurement of KWH for the T5.  I will start recording this when it is time to turn on the light – around 3 to 5 days after putting seeds into the rock wool.  Most likely it will be the biggest recurring cost.

Approximate Cost of Germination Station

One time cost:

Part Cost
T5 lighting $50
Dome Home $5
Heat mat $20
Timer $12
TDS Tester $17.01
TOTAL $104.01

The price of the parts add up quickly. No surprise the largest cost is for lighting.  I like that I don’t have to use more expensive LEDs for seed starting. On the positive side,  all the parts can be used again.

Recurring cost:
Part Cost
Buttercrunch lettuce seeds $0.13
Rock wool starters $0.18
Nutrients $0.05
Energy TBD
TOTAL $0.36

I am curious to know the energy costs.  As I noted earlier, energy is probably the biggest recurring cost.  Also, the $0.36 assumes 100% of the plants make it to salads and hamburger buns.  This is unrealistic.  I’ll adjust as I see how many plants survive.

Time To Start

And off I go.  I planted approximately 24 seeds in 12 rock wool starter cubes.  I’ll add a post as the plants and I continue our journey.

What’s Next

I’ll get started on setting up the Growth Station in the next post.  This will include Arduino + wireless to sense and automate plant care.  I will be relying on several of the project I have discussed in earlier posts.  Hopefully, I’ll get to a system that will allow me to be lazy yet well stocked with tasty lettuce.

Comments Since Posting

I’m thrilled to hear about similar projects as well as different aspects to compare contrast.  Here are some of the comments:

theUrbanGreenhouse 1 point 4 hours ago

I plan on doing the same thing pretty soon. Just bought a little 8×6 greenhouse for the backyard and got some more material for vertical systems. You’ll be a little ahead of me so I’ll be looking forward to some updates.

Two things I can add right now: My energy cost for running two T5 fixtures for a month using an 18-6 lighting schedule was just under $4. I know we have different cost/kwh but that should give you some sort of guesstimate. Also, lettuce has very easy nutrient requirements so when it comes to introducing nutes definitely go easy on them, maybe even a bit less than 1/4 strength. I remember my 1/4 strength of the GH Flora line was a lot higher eC than the 1/4 strength of the Canna AquaVega.


[–]contentkaiser 1 point 5 days ago

This is exactly what I do (off-season) with my hydro set-up! You are working with a much smaller scale system, but it’s still a fun experiment. I’d recommend throwing in a tray of sprouting seeds (don’t even need light/nutes) and a tray of microgreens in perlite under one of your fluorescent tubes – that’ll give you some low maintenance variety and some nutritive additions.

If you’re feeling super adventurous – you can also keep a plastic tote underneath your hydro system w/ mealworms in it, just add vegetable waste and kitchen scraps (dry) and dry mealworms to put on your salads for a little protein.


]Jmadman311 1 point 5 days ago

I’d be very surprised if you got an accurate pH and that it would stay stable over time. pH is one of the most important things to control and you should consider getting a cheap meter to do so!!

Also, did you soak your rockwool before use? I have read that the pH of the rockwool environment tends to be quite high, above 8, unless the cubes are pretreated by soaking them in a mild acid like l


[–]mikeg53 1 point 4 days ago

Cool. Look forward to it.

As a point of reference, my 446g romaine head fed 4 people with nice size salads on Saturday.

It took 104 days from seed planting to eating. This guy was in the middle of the garden and I neglected to cut him when he really needed to be – it was ready in 75-80 days, the last 4 weeks didn’t do much for growth except make an even more dense center pack of leaves.




[–]RamblingMutt 1 point 4 days ago

I just started growing lettuce as well, as an experimentation chamber to hopefully move onto a large NFT system. The seeds have but a few wee roots right now.


Fidget likes to watch the bubbles, which I know don’t really need to be on but I like it to look all sciency.

emon juice.

In any case I’m looking forward to more updates!




Thanks for reading this far.  Please find many things to smile about.