My goals for this post include:

  • giving an update on how well the indoor plants are growing in their hydroponics home
  • reflect on the different setups
  • evolve my understanding and efficiency of an indoor home DIY hydroponics system.

In addition to the DIY hydroponics systems I have started, I bought two hydroponics systems targeted at the “busy person” who just wants to grow fresh herbs and vegetables.  These are not for the person who is into setting up and tweaking the ultimate system.  Rather the average home owner who is very busy but is interested into positive changes in their home life.  I wanted to look into a few home hydroponics systems since my interest is to positively change home lives to include the most engaging plant growing systems. 

I’ll start by discussing how my DIY hydroponics system is doing.

My DIY Hydroponics System

I covered the setup of my hydroponics system in this post.

Here’s a picture of the DWC bucket growing the tomato plant:

Tomato DIY

Here’s a picture of the other DWC bucket growing three other plants:

3 Plant DIY

The Leaves

The Cucumber

The cucumber plant had brown and yellow on its ends.


I thought this might be due to to high a nutrient concentration.  I asked on the hydro subreddit and received this response:

[–]johnmal85  10 hours ago

Probably. Check your pH also. As it could be a lockout. That rockwool seems a bit wet. I like to top water until the roots hit the air layer. Don’t let the rockwool sit in the solution.

As shown in this chart of pH levels, the recommended range for a cucumber plant’s pH is 5.8-6.0.  The current reading of 4.95 is too low.  I added pH UP and now the pH level is around 6.0.  So as @johmal85 points out, the cucumber plant is probably not receiving the right nutrients.  Hopefully I’ve fixed that problem!

I am also glad he noted the wetness of the rock wool.  I have the water level too high.  I will follow John’s recommendation about water level.  Next time, when I build a new hydroponics system I want to have a mechanism that makes sure the water level is at this point.  The simplest is a run-off at this level or a line that identifies the correct water level.  I like the idea of the run off better.  However, it makes me think about moving from a DWC system to one that always adds the right amount of water without me checking it.

Also, next time, I will not start seeds inside the hydroponics system.  John provided recommendations for seed starting that I will use when I start plants from seeds:

[–]johnmal85 1 point 1 hour ago

They have things known as domes that are great for cuttings and seedlings. They keep the co2 levels high and the humidity high as well as reduce the wind that will cause the plant to sweat too much. You can make your own. Its like a tray that sits above another tray that contains water and a dome over the top with vents so you can control humidity. When the roots emerge a few inches out of the rockwool you can place it in the dwc and put the clay pellets around it.

Don’t transplant your plant now. Keep it in the dwc and drop the water level and continue to top water. Make sure the light is high and that the ambient temp isn’t too hot. Don’t have a fan blowing on it 24/7 as it will sweat too much. Seedlings need next to nothing for 3 weeks, but your seedling looks like it might be close to the age of where it needs a tiny bit of nutes. Whatever the container for your nutes says for seedlings, cut it in half at least. Those companies recommend way too heavy a dose so that people buy more product.

Good luck!

from johnmal85 via /r/hydro/ sent 3 hours ago

Ps. You can use this same technique to root cuttings and is quicker than seedlings in the long run. Just learn correct cutting procedure and add some root gel or powder and you’re good to go. Rapid rooters are great for seedlings and cuttings alike. Has mycorrhizae and made of composted material with good air to moisture balance.

Empty Cube

One of the plants in the three plant bucket did not germinate.  I don’t know why so I removed the rock wool and replaced with a new rock wool in which I inserted Nevada Lettuce seeds.  Besides the oops! moments noted above (ensuring proper pH – for lettuce this ranges between 6.0-6.5, using a different method for seed starting), a new next time is to ensure compatible plants at the pH and TDS measurements – most likely the same type of plant in a multi plant bucket.

Reviewing Measurements

I took measurements with a variety of measuring tools while I get the networking going on my hydroponics sensor network.  The water temperature is about right.  Each bucket has an adjustable heater set to 72F/22C.  Here’s what I said before about “best” values for LUX and PAR. I haven’t changed the lighting. So the values are still low. I’ll wait to see how the plants turn out before I add additional LEDs.  I started using a pH meter that was inaccurate and ended up putting too much pH DOWN in the buckets.  I got some pH UP and now the buckets measured a pH value of close to 6.  Details of the pH meter I ended up using is discussed below.  This is my first look at matching TDS values to a specific plant.  Next time if I grow more than one plant in a system that shares nutrients, I will check first if their ranges overlap.  This time however, I did not.   According to this chart – of which I can’t say is authoritative (if you know of an authoritative source for ppm/tds/EC please let me know!), the TDS values for:

  • Tomatoes should range from 1400-3500.  The tomato’s TDS value measured at 2180.  On one hand I can see why a TDS reading may not be that meaningful.  After all, while it is measuring Total Dissolved Solids, I have no idea what nutrients are actually left.  For now I will not add any nutrients.
  • The other bucket has three plants – cucumber (TDS should range between (1190-1750), spinach (1260-1610), and lettuce (560-840).  The TDS value I measured was 1730 – which is way too high for the lettuce.  Next time I will not put these plants in the same bucket.  I will try to lower the TDS to the the lower end of spinach (around 1260 ppm) by changing the water in the bucket.  This will also give me the chance to see if algae is starting to grow.  In either case, I plan to clean the buckets.  Googling provided a vast amount of recommendations for how to clean.  I am going to try the vinegar method and use about 1 cup of vinegar per bucket.  It made sense to me that vinegar would be a good addition to cleaning since it is an acid.  I figured the worst that could happen is the pH could be more acidic when the bucket is filled with filtered water.

Other Concerns

Besides the adjustments noted above, I was concerned if the LED system would get too hot.  I have both fans going on the CPU coolers.  With this arrangement, the LED enclosure and the heat sinks measured a temperature of 73F/22.8C.  I thought these heat sinks might be overkill – but turns out they are great – both from working well and price point (relative to heat sinks that are “designed” for a particular LED).

Additions to the CoGs

I had to purchase the pH UP.  Previously, I recorded the CoGs for the two hydroponic systems (without LEDs) to be $39.28 for the 1 plant and $38.56 for the 3 plant.  The pH UP cost $15.17.  The package also came with pH DOWN – which I already had.  Plus I assume the bottles will last through multiple usages.  For this CoGs model, I’ll assume 1/3 of the ph UP which adds $2.53 cents.  I divided $15.17 by 6 to get to $2.53 – assuming 1/3 of each bottle would be used through a plant’s growing cycle and there are 2 bottles.

The updated CoGs – not including LED system:   


1 plant bucket

3 plant bucket

Previous CoGs



Current CoGs



Measuring the PH

 Awhile back, I bought a pH sensor kit from Sparkfun.  


The kit lists for $105.95.  Wow – talk about sticker shock!  Even though at the time I bought it, Sparkfun was running a 20% off sale…I felt a bit of shock at the price.  The great thing is it is a complete kit that comes from Atlas Scientific.  Atlas Scientific seems to take pride in providing tools that are accurate.  Atlas Scientific has two YouTube videos that walked me through setting the sensor up with my Arduino. One youTube video helps with putting the “PH stamp” on the breadboard and connecting it with an Arduino.  The other youTube video that goes through sending commands and calibrating the PH’s.

It’s a very simple sensor to use.  The sketch I used is based on the Arduino example code found within the Sparkfun description of the PH Sensor.  This data sheet gives the commands that can be sent to the sensor and how to calibrate the sensor. 

pH Sensor With Arduino

I found measuring the pH by using the sample script – calibrating, then taking a reading – to be more cumbersome than it needed to be.  I ran across an aquaponics project on Sparkfun that takes Arduino integration with this sensor a step forward. In the future, I will build an automated pH dispensing system that uses a pH sensor to determine the pH and then adjusts the pH level automatically.  I say in the future because I still haven’t evolved the base system (data collection) to the next level.  I suppose the good news is there is always one more thing to look forward to learning and building.

A concern I wanted to start addressing is exploring alternatives to the Atlas Scientific pH sensing kit.  The cost is too high to build more than a test unit.  The first thing to note is I don’t need a kit.  Rather a probe, BNC connector, and pH circuit to read the pH.

I asked in the comments section of the post for the Sparkfun project if anyone had recommendations for alternatives.  This answer can get me started:

reply | report My 3 Probes choices are (from cheapest to most expensive) K1B0 Style This one is a pretty good probe but the lead to pretty short and you shouldnt leave this submerged for long periods(reference can be refilled, so it can leak).

Mid Range, durable This one is a tough and durable probe, I had pretty good experience with it, it sometimes has issues reading right after shipping leave it upright for a few minutes and it should start reading as normal.

Higher End These are generally my favorite probes, they last forever, are of a good quality and aren’t too expensive for their performance! If you plan on doing long term in situ readings this is definitely worth the extra price.

If you need more lab grade probes I highly recommend Omega as the source. Their probes are very expensive, but are extremely high quality! Omega. Hope this helps some source more appropriate probes for their needs!

As I put my build list together, I need to figure out which to buy of:

This project should be fun – but it will have to wait for a bit.
That’s it for my DIY hydroponics system.  
To round this post out, I’ll add in my experience with two hydroponics products that I bought to try out.  Neither is of interest to a person who is very serious about hydroponics.  Rather, these are targeted at folks that want to grow an indoor plant in a self-contained system where they don’t have to know much.  I was curious to compare and contrast these products.  Now I know….



AeroGarden 3 with Gourmet Herb Seed Kit, Yellow   $100


My Experience 

I had heard of AeroGrow’s AeroGardens awhile back, although I never got interested enough to purchase one.  I wanted to try one because they seem to be a popular form of indoor hydroponics gardening for folks that know little if anything about gardening and hydroponics.  I was curious to see just how easy one is to use and – of course – how well plants grow.  I was also interested in the initial and ongoing costs.  

The Plants

The Gourmet seed kit included basil, thyme, and dill.   I started using the AeroGarden 3 at the end of August.  Here are the plants as of today.  I have cut the basil down several times.  Now it is getting bushy, which I am fine with although it seems to start crowding out the more delicate thyme.  So far I have been able to harvest both basil and thyme.  I am now harvesting enough that I need to know more dishes into which I can use these herbs.  I’m looking forward to the mint.  I put mint in salads, beverages, tzatziki…

AeroGrow 11/05/2013

As the three seed starters got used to their new lives, the dill did not grow.

Aero Garden Dill Starter

I emailed AeroGrow support and was sent mint at my request as a replacement AeroGrow sent this free of charge and with free shipping.  As our lives integrate more and more technologies, it is no longer acceptable for a company not to have strong support.  To me it is something I will pay more for because it is a key feature of happy enjoyment of the experience they are selling me.  Contrast to when I purchase a Yoga mat.  While the mat is a key part of a happy Yoga experience, it is easy for me to figure out if there is something wrong with the mat and easy to replace.  Things that depend on software and hardware – which these “smart” hydroponics systems are – should not have to be debugged by the consumer.  On the other hand, we should expect to pay for this support.  I have worked in support.  My experience is one of constantly increasing my knowledge, honing down my problem solving skills, and improving on my relationship skills.  All took time and focus. 

It was great to see AeroGrow has prompt support that is there to solve the challenges.  They seem to care about customer satisfaction.

Light and Plant Food 

AeroGrows uses a DWC hydroponics method.  My AeroGrow 3 uses a Compact Florescent Lamp (CFL) to provide light to the plants.  I noted in this post the light characteristics.  The color temperaturewas 5,185 K.  The LUX was 3,185 lux.  The AeroGrow 3 comes with a small bottle of nutrients.  The label states “One-Part Nutrient for Seed Starting, Vegetative Growth, Flowering and Fruiting.  

Every two weeks, a little red light goes on.  This is how the AeroGrow reminds me to add nutrients.  It is becoming habitual…I see the light on, I add 4 ml of nutrients.  I turn the light off.  Two weeks go by.  I see the light on… [repeat every two weeks].

 AeroGrow 3 CFL Bulb AeroGrow Liquid Nutrients 
 CFL Light  Liquid Nutrients


The AeroGrow 3 sits next to our toaster in the kitchen.  I love the convenience of snipping off an herb right where I am cooking.  I can’t believe how lazy I am – but sometimes it seems like a chore to walk 100 feet out our back door to snip some rosemary.  This is particularly true when it is cold and rainy.

Once and awhile I check the water level and fill as needed.   Every two weeks, a little red light goes on.  This is how the AeroGrow reminds me to add nutrients.  So every two weeks I measure out 3ml of the nutrients that came with the AeroGrow 3 and add it into the water.

I forgot why, but I signed up for their marketing email.  Now I get an email from AeroGarden practically daily letting me in  on “save 15%” …and other deals I am silly not to buy.




I’ve decided not to continue using the AeroGrow 3 after these plants are done with their lifecycle.  While I like that it is pretty mindless to grow the prescribed plants, the things I don’t like outweighed them.  These things included: 1) buying proprietary seed kits and nutrients from AeroGarden.  Not only are these expensive, but it limits the kind of plants I can grow. 2) It would be difficult and perhaps impossible to grow enough to pay back for the cost of the unit, seed starters, and nutrients.  Ultimately, less expensive is not my goal but rather freshness, knowing where a vegetable, fruit, or plant comes from and how it was grown, as well as convenience.  So while I keep cost in mind, this is not the highest priority in using an hydroponics system.  3) not extensible.  The AeroGrow 3 is the least expensive and smallest of the AeroGrows.  In fact, AeroGarden – under the recent strategic partnership with Miracle Gro (discussed in their 10-K) has recently come out with the AeroGarden Ultra LED for $350.  I have to admit I would love to give this one a twirl but it is much more than I want to spend. 

Click & Grow


Starter Kit with Mini tomato  $100


My Experience


I found this review on Amazon.com.  Unfortunately, it parallels my own experience to the point that I have nothing more to say regarding the Click & Grow.  On to better times!

34 of 41 people found the following review helpful
1.0 out of 5 stars Update, from five stars to one., September 30, 2012
DR. B (Wisconsin) – See all my reviews
Amazon Verified Purchase(What’s this?)
This review is from: Click and Grow – Cockscomb Starter Kit (Lawn & Patio)

I bought some of these as a gift, not really knowing what to expect. First everyone just loved them and thought they were so cool.

Second, very easy set up, insert batteries and water and that is about it. Nice feature is blinking light tells you: all is well (green), or needs water or needs new batteries.