Products

Review of MUGFA (Aerogarden type) Countertop Hydroponic Units

Scott BuchananLeave a comment

Last year about this time, as the outside world got darker and colder, and the greenery in my outdoor planters shriveled to brown – – I resolved to fight back against seasonal affect disorder, by growing some lettuce and herbs indoors under a sun lamp.

After doing some reading and thinking, I settled on getting a countertop hydroponics unit, instead of rigging a lamp over pots filled with dirt indoors. With a compact hydroponics unit there is no dirt, no bugs, it has built-in well-designed sun lamp on a timer, and is more or less self-watering.

These systems have a water tank that you fill with water and some soluble nutrients. There is a pump in the tank that circulates the water. There is a deck over the tank with typically 8 to 12 holes that are around 1 inch diameter. Into each hole you put a conical plug or sponge made of compressed peat moss, supported by a plastic basket. On the top of each sponge is a little hole, into which you place the seeds you want to grow.

A support basket with a dry (unwetted, unswollen) peat moss grow sponge/plug in it.

As long as you keep the unit plugged in, so the lights go on when they should, and you keep the nutrients solution topped up, you have a tidy automatic garden on a table or countertop or shelf.

The premier countertop hydroponics brand, which has defined this genre over the past twenty years, is Aerogarden. This brand is expensive. Historically its larger models were $200-$300, though with competition its larger models are now just under $200.  Aerogarden tries to justify the high cost by sleek styling and customizable automation of the lighting cycles, linked into your cell phone.

I decided to go with a cheaper brand, for two reasons. First, why spend $200 when I could get similar function for $50 (especially if I wasn’t sure I would like hydroponics)? Second, I don’t want the bother and possible malfunction associated with having to link an app on my cell phone to the growing device and program it. I wanted something simple and stupid that just turns on and goes.

So I went with a MUGFA brand 18-hole hydroponics unit last winter. It is simple and robust. The LED growing lights are distributed along the underside of a wide top lamp piece. The lamp has a lot of vertical travel (14“), so you could accommodate relatively tall plants. The lights have a simple cycle of 16 hours on, 8 hours off. You can reset by turning the power off and on again; I do this once, early on some morning, so from then on the lights are on during the day and the evening, and off at night.  The water pump pumps the nutrient solution through channels on the underside of the deck, so each grow sponge has a little dribble of solution dribbling onto it when the pump cycle is on. I snagged a second MUGFA unit, a 12 hole model, when it was on sale last spring. The MUGFA units come complete with grow sponges/plugs, support baskets/baskets for the sponges, nutrients (that you add to the water), clear plastic domes you put over the deck holes while the seeds are germinating, and little support sticks for taller plants. You have to buy seeds separately.

Images above from Amazon , for 12-hole model

I have made a couple small modifications to my MUGFA units. The pump is not really sized for reaching 18 holes, and with plants of any size you’re likely not going be stuffing 18 plants on that grow deck. Also, the power of the lamp for the 18-hole unit (24 W) is the same as the 12-hole unit; the LEDs are just spread over a wider lamp area. That 24W is OK for greens that don’t need so much light, but may only be enough to grow a few (mini) tomato plants. For all these reasons, I don’t use the four corner holes on the 18-hole unit. Those corner holes get the least light and the least water flow. To increase the water flow to the other 14 holes, I plugged up the outlets of the channels on the underside of the deck leading to those four holes. I cut little pieces of rubber sheeting, and stuffed them in channel outlets for those holes.

The 12-hole unit has a slightly more pleasing compact form factor, but it has a minor design defect [1]. The flow out of the outlet of each of the 12 channels under the deck is regular, but not very strong. Consequently, the water that comes out of each outlet drops almost straight down and splashes directly into the water tank, without contacting the grow sponge at that hole. The waterfall noise was annoying. The fix was easy, but a little tedious to implement. I cut little pieces of black strong duct tape and stuck them under the outlet of each hole, to make the water travel another quarter inch further horizontally. Those little tabs got the water in contact with the grow sponge basket. The picture below shows the deck upside down, showing the water channels under the deck going to each hole. There is a white sponge basket sticking through the nearest hole, and my custom piece of black duct tape is on the end of the water channel there, touching the basket. (In order to cover the exposed sticky side of the duct tape tab that would be left exposed and touching the basket, I cut another, smaller piece of duct tape to cover that portion of the tab, sticky side to sticky side.). This sounds complicated, but it is straightforward if you ever do it. Also, many cheap knock-off hydroponics units don’t have these under-deck flow channels at all. With MUGFA you are getting nearly Aerogarden type hardware for a third the price, so it is worth a bit of duct tape to bring it up to optimal performance.

12-hole MUGFA deck, upside down with one basket;  showing my bit of black duct tape to convey water from the channer over to the basket.

Some light escapes out sideways from under the horizontal lamps on these units. As an efficiency freak, I taped little aluminum foil reflectors hanging down from the back and sides of the lamp piece, but that is not necessary.

To keep this post short, I have just talked about the hardware here. I will describe actual plant growing in my next post. But here is one picture of my kitchen garden last winter, with the plants about 2/3 of their final sizes:

The bottom line is, I’ve been quite satisfied with both of these MUGFA units, and would recommend them to others. They provided good cheer in the dark of winter, as well as good conversations with visitors and good fresh lettuce and herbs. An alternate use of these types of hydroponics units is to start seedlings for an outside garden.

ENDNOTE

[1] For the hopelessly detail-obsessed technical nerds among us – – the specific design mistake in the 12-hole model is subtle. I’ll explain a little more here.        Here is a picture of the deck for the 18-hole model upside down, with three empty baskets inserted. The network of flow channels for the water circulation is visible on the underside. When the deck is in place on the tank, water is pumped into the short whitish tube at the left of this picture, flows into the channels, then out the ends of all the channels. (Note on the corner holes here, upper and lower right, I stuck little pieces of rubber into the ends of the flow channels to block them off since I don’t use the corner holes on this model; that blocking was not really necessary, it was just an engineering optimization by a technical nerd).

 Anyway, the key point is this: the way the baskets are oriented in the 18-hole model here, a rib of the basket faces the outlet of each flow channel. The result is that as soon as the water exits the flow channel, it immediately contacts a rib of the basket and flows down the basket and wets the grow sponge/plug within the basket. All good.

The design mistake with the 12-hole model is that the baskets are oriented such that the flow channels terminate between the ribs. The water does not squirt far enough horizontally to contact the non-rib part of basket or the sponge, so the water just drips down and splashes into the tank without wetting the sponge. This is not catastrophic, since the sponges are normally wetted just by sitting in the water in the tank, but it is not optimal. All because of a 15-degree error in radial orientation of the little rib notches in the deck. Who knows, maybe Mugfa will send me a free beta test improved 12-hole model if I point this out to them.

LinkedIn is OK, Actually

James Bailey2 Comments

LinkedIn has its problems, but so does every other social network.

I joined LinkedIn out of college because it seemed like something you were supposed to do if you want a job someday, but I never checked it because the academic job market makes little use of LinkedIn. In 2013 LinkedIn added social media features like a newsfeed, but I still never spent time there. Facebook and Twitter seemed more interesting, and like many people I’ve always been allergic to “networking” or other social settings where one person is just trying to get something from another. It seemed like a recipe for posts that are cringe, soulless, or desperate.

But over the past couple years, I’ve found myself spending more time there- and not because I’m looking for a job or looking to hire. Some of the posts are genuinely interesting, and it is a nice way to keep up with what people I know are up to. Either LinkedIn got better or I got worse.

I find that LinkedIn is particularly good for staying in touch with my old students. I always told my students they could still e-mail me or stop by my office after the semester is over, but they almost never do; that takes a lot of thought and energy. Social networks are the ideal way to keep in touch with “weak ties“, but you have to find the right one. Facebook was the best for this when it was ubiquitous, but now it is becoming more common for Americans not to have or not to check Facebook, especially young ones (plus it was always a bit too personal for former students). Twitter has never been something that most people have, and the more popular networks are either too personal (Instragram, Snap et c) or too impersonal where almost all content users see comes from people they don’t know (TikTok, Youtube, et c).

LinkedIn by contrast is ubiquitous and just the right amount of personal. It also seems to be increasingly a good place to share interesting writing. I like much of what I read there, and my writing gets a good reception; I tend to get more engagement for EWED posts on LinkedIn than on X and Facebook despite having fewer connections there than Facebook friends or Twitter followers. Yes, you’ll still see some cringe posts there, but it beats the angry political posts that are ubiquitous on Facebook and especially X.

You can find me on LinkedIn here, if you dare.

Now Published: Prohibition and Percolation

Zachary Bartsch2 Comments

My new article, “Prohibition and Percolation: The Roaring Success of Coffee During US Alcohol Prohibition”, is now published in Southern Economic Journal. It’s the first statistical analysis of coffee imports and salience during prohibition. Other authors had speculated that coffee substituted alcohol after the 18th amendment, but I did the work of running the stats, creating indices, and checking for robustness.

My contributions include:

  • National and state indices for coffee and coffee shops from major and local newspapers.
  • A textual index of the same from book mentions.
  • I uncover that prohibition is when modern coffee shops became popular.
  • The surge in coffee imports was likely not related to trade policy or the end of World War I
  • Both demand for coffee and supply increased as part of an intentional industry effort to replace alcohol and saloons.
  • An easy to follow application of time series structural break tests.
  • An easy to follow application of a modern differences in differences method for state dry laws and coffee newspaper mentions.
  • Evidence from a variety of sources including patents, newspapers, trade data, Ngrams, naval conflicts, & Wholesale prices.

Generally, the empirical evidence and the main theory is straightforward. I learned several new empirical methods for this paper and the economic logic in the robustness section was a blast to puzzle-out. Finally, it was an easy article to be excited about since people are generally passionate about their coffee.

Bartsch, Zachary. 2025. “Prohibition and Percolation: The Roaring Success of Coffee During US Alcohol Prohibition.” Southern Economic Journal, ahead of print, September 22. https://doi.org/10.1002/soej.12794.

My Perfunctory Intern

Zachary Bartsch1 Comment

A couple years ago, my Co-blogger Mike described his productive, but novice intern. The helper could summarize expert opinion, but they had no real understanding of their own. To boot, they were fast and tireless. Of course, he was talking about ChatGPT. Joy has also written in multiple places about the errors made by ChatGPT, including fake citations.

I use ChatGPT Pro, which has Web access and my experience is that it is not so tireless. Much like Mike, I have used ChatGPT to help me write Python code. I know the basics of python, and how to read a lot of of it. However, the multitude of methods and possible arguments are not nestled firmly in my skull. I’m much faster at reading, rather than writing Python code. Therefore, ChatGPT has been amazing… Mostly.

I have found that ChatGPT is more like an intern than many suppose:

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We’re All Magical

Zachary BartschLeave a comment

The widespread availability and easy user interface of artificial intelligence (AI) has put great power at everyone’s fingertips. We can do magical things.

Before the internet existed we would use books to help us better interpret the world.  Communication among humans is hard. Expressing logic and even phenomena is complex. This is why social skills matter. Among other things, they help us to communicate. The most obvious example of a communication barrier is language. I remember having a pocket-sized English-Spanish dictionary that I used to help me memorize or query Spanish words. The book helped me communicate with others and to translate ideas from one language to another.

Math books do something similar but the translation is English-Math. We can get broader and say that all textbooks are translation devices. They define field-specific terms and ideas to help a person translate among topic domains, usually with a base-language that reaches a targeted generalizability. We can get extreme and say that all books are translators, communicating the content of one person’s head to another.

But sometimes the field-to-general language translation doesn’t work because readers don’t have an adequate grasp of either language. It isn’t necessarily that readers are generally illiterate. It may be that the level of generality and degree of focus of the translation isn’t right for the reader. Anyone who has ever tried to teach anything with math has encountered this.  Students say that the book doesn’t translate clearly, and the communication fails. The book gets the reader’s numeracy or understood definitions wrong. Therefore, there is diversity among readers about how ‘good’ a textbook is.

Search engines are so useful because you can enter some keywords and find your destination, even if you don’t know the proper nouns or domain-specific terms. People used to memorize URLs and that’s becoming less common. Wikipedia is so great because if you want to learn about an idea, they usually explain it in 5 different ways. They tell the story of who created something and who they interacted with. They describe the motivation, the math, the logic, the developments, and usually include examples. Wikipedia translates domain-specific ideas to multiple general languages of different cognitive aptitudes or interests. It scatters links along the way to help users level-up their domain-specific understanding so that they can contextualize and translate the part that they care about.

Historical translation technology was largely for the audience. More recently, translation technology has empowered the transmitters.

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A Forgotten Data Goldmine: Foreign Commerce and Navigation Reports

Zachary BartschLeave a comment

Economists rely on trade data. The historical Foreign Commerce and Navigation of the United States reports detailed monthly figures on imports, exports, and re-exports. This dataset spans decades, providing a crucial resource for researchers studying price movements, consumption patterns, and the effects of war on global trade.

The U.S. Department of Commerce compiled these reports to track the nation’s commercial activity. The data cover a vast range of commodities, including coffee, sugar, wheat, cotton, wool, and petroleum. Officials recorded trade flows at a granular level, enabling economists to analyze seasonal fluctuations, wartime distortions, and postwar recoveries. Their inclusion of re-export figures allows for precise estimates of domestic consumption. Researchers who ignore re-exports risk overstating demand by treating imports as goods consumed rather than goods in transit.

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How FRASER Enhances Economic Research and Analysis

Zachary BartschLeave a comment

Most of us know about FRED, the Federal Reserve Economic Data hosted by the Federal Reserve of St. Louis. It provides data and graphs at your fingertips. You can quickly grab a graph for a report or for a online argument. Of course, you can learn from it too. I’ve talked in the past about the Excel and Stata plugins.

But you may not know about the FRED FRASER. From their about page, “FRASER is a digital library of U.S. economic, financial, and banking history—particularly the history of the Federal Reserve System”. It’s a treasure trove of documents. Just as with any library, you’re not meant to read it all. But you can read some of it.

I can’t tell you how many times I’ve read a news story and lamented the lack of citations –  linked or unlinked.  Some journalists seem to do a google search or reddit dive and then summarize their journey. That’s sometimes helpful, but it often provides only surface level content and includes errors – much like AI. The better journalists at least talk to an expert. That is better, but authorities often repeat 2nd hand false claims too. Or, because no one has read the source material, they couch their language in unfalsifiable imprecision that merely implies a false claim.

A topical example would be the oft repeated blanket Trump-tariffs. That part is not up for dispute. Trump has been very clear about his desire for more and broader tariffs. Rather, economic news often refers back to the Smoot-Hawley tariffs of 1930 as an example of tariffs running amuck. While it is true that the 1930 tariffs applied to many items, they weren’t exactly a historical version of what Trump is currently proposing (though those details tend to change).

How do I know? Well, I looked. If you visit FRASER and search for “Smoot-Hawley”, then the tariff of 1930 is the first search result. It’s a congressional document, so it’s not an exciting read. But, you can see with your own eyes the diversity of duties that were placed on various imported goods. Since we often use the example of imported steel and since the foreign acquisition of US Steel was denied, let’s look at metals on page 20 of the 1930 act. But before we do, notice that we can link to particular pages of legislation and reports – nice! Reading the Smoot-Hawley Tariff Act’s original language, we can see the diverse duties on various metals. Here are a few:

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Keeping Receipts

Zachary Bartsch1 Comment

Online shopping is convenient and even the norm for many items. Going to the store sounds like a time-consuming labor or an exceptional outing. My family, for example, lives in a suburban location that doesn’t have well-priced grocery home delivery. Shipping only works for some non-perishables. So, for many items we order online and do ‘drive-up pick-up’. We don’t even need to go into the store for many items. And reordering the same items repeatedly is a breeze.

We are also accustomed to the ability to return things. If your blender breaks on your first smoothie, then no worries – you can return it. If the chocolate cookies don’t taste like chocolate? Return it – satisfaction guaranteed. You can buy three pairs of shoes in different sizes and then keep the ones you want at the original sale price. Return the others.

For me, besides the time saved and convenience, a major factor in my decision to make purchases online is the documentation. I don’t need to save the receipt in a shoe box, Ziploc, or file drawer – the online retailer keeps an archive of all my purchases. Often this includes the date, amount, and shipping details including delivery date. There’s a super convenient digital paper trail.

If I need to contact a seller in order to exercise a warranty, then I have their contact information. I don’t need to retain the product packaging or investigate the brand at a future inopportune time. For example, I recently bought a Little Tykes water table for my kids. As I was assembling it on Christmas Eve I realized that I was missing a small part. I was able to work around it. But I was also able to immediately contact the manufacturer with a copy of my invoice. I emailed the date of purchase, the product model number, and the instruction manual had conveniently included part numbers. They were able to ship me the parts after a single email. Online shopping, and the resulting trail of evidence, makes the process much more practical than keeping paper records in a likely unorganized fashion.

There are other benefits to the paper trail. Back before widespread online shopping, retailers would often offer rebates as a sales strategy. In the year 2004, I bought a computer hard drive for $120 before a $40 mail-in rebate. The retailer (or manufacturer, I can’t remember) was hoping that people saw the post-rebate price and then failed to redeem it. And that often happened.  You needed to fill out a rebate form on an index card, cut the UPC bar code of the product packaging, and then mail them with your receipt to the company rebate department in a stamped envelope. If you dragged your feet, then you’d probably lose an important piece of the crucial combination and lose out on your $40 rebate. If the items were lost in the mail, then you were shucks-out-of-luck. Now, rebates have gone the way of the dodo since receipts are automatically retained and retrievable.

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What is vision insurance good for?

James Bailey5 Comments

The answer sure seems to be “nothing”. I just went for an eye exam for the first time since Covid and realized that I’ve been wasting my money by paying for vision insurance.

The problem isn’t the eye exam- that went fine, and was covered fine with a $35 copay. But it was covered by my health insurance, not my vision insurance. So what is the vision insurance good for, if it doesn’t cover eye exams?

The answer is supposed to be “glasses”. It is supposed to cover frames up to $150 with a $0 copay, and basic lenses with a $25 copay, from in-network providers. That sounds ok- but there are two problems.

One is that almost none of the in-network providers (like Glasses dot com or Target optical) appear to actually offer lenses where the $25 copay applies; instead the minimum lens price is at least $85.

The second problem is that the premiums are high enough that even if I use them to get $25 glasses (which I eventually found I could through LensCrafters), it wouldn’t be worth it. They don’t sound high at first, which is how I got suckered into signing up for this scam in the first place. It’s just $5/month for single coverage; that sounds like nothing, especially for an employer benefit. It is a rounding error compared to health insurance premiums, and it comes out of pre-tax money. A small waste, but still a waste. Why?

Glasses are just so cheap if you can avoid the monopoly retailers and get them somewhere like Zenni. Zenni will sell you perfectly functional (and IMHO good-looking) prescription eyeglasses for $16. Their frames start at $6.95, lenses at $3.95, and shipping at $4.95. Catch a sale, or order enough to get free shipping, and you could actually get glasses for well under $16.

Or you can do what I did- order glasses from Zenni with premium options that pushed them up to $50- and find it is still cheaper than using the insurance I already paid for to get the cheapest pair available at most of their in-network retailers. The cheapest possible deal with insurance would be to pay $60/year in premiums, get glasses as often as the insurance allows so as not to waste the benefit (every 12 months- much more often than I find necessary), find frames listed under $150 to get for $0 copay, and find an in-network provider that actually offers lenses for the $25 copay. In this best-case scenario you are still paying $85 per pair of glasses. Given that the $60 in premiums came from pre-tax money, perhaps you can argue that it was really more like $40 in real money; but you can also buy glasses from a competitive retailer like Zenni using pre-tax money from an HSA or FSA.

So as far as I can tell, vision insurance really is useless. I certainly decided not to use it for my latest pair of glasses even though I had already paid years of premiums; Zenni was still much cheaper for a comparable product. I’m dropping vision insurance now that open enrollment is here. My take-home pay will be going up, and EyeMed will stop getting my money for nothing.

Is there anyone vision insurance makes sense for? I think it could makes sense for someone who really wants brand name glasses, or for someone who really wants to get their glasses in-person at the optometrist, and wants new glasses every year. For everyone else, run the numbers for your own plan, but I suspect you would also be better off just buying glasses directly.

Disclaimer: This post is not sponsored & doesn’t use affiliate links; Zenni is the best option I currently know of, but I’d be happy to hear of other competitive retailers you think are better, or an argument for when vision insurance is actually useful.

Robinhood’s Casino Comps

James Bailey2 Comments

I just got the new Robinhood Gold credit card after 4 months on their waitlist. It offers 3% cash back on everything- except travel, which is an even better 5%. This seems to be a much better deal than the typical credit card (which offers ~0-1% back in cash or equivalents), and even better than the previous best alternative I know of (the Citi Double Cash, which pays 2% back). So, is there a catch?

As far as I can tell, there are two, but one is minor and the other is avoidable.

The minor catch is that while they advertise the Gold Card as having no annual fee, you need to be a Robinhood Gold member to get it. Robinhood Gold has a $50/year fee, though it comes with other benefits, and getting the extra 1%+ back on the credit card will itself pay for the fee assuming you spend at least $5k/yr on the card.

The potentially major catch, and the reason I assume Robinhood is offering such a good deal, is that they want to entice you to open a brokerage account and to make bad decisions with that account that make them money. Much like a casino that offers you free drinks and cheap hotel rooms in the hope that you will choose to gamble and end up losing way more than the cost of the “complimentary” things they gave you. This is a major risk, but if you know what to avoid you can still come out ahead. The last time my friends dragged me to a casino I got handed plenty of free drinks despite the fact that I never gambled. Similarly, Robinhood might nudge its users to lose money in ways large (options) and small (overtrading with market orders).

But while Robinhood’s interface might suggest these bad choices, it absolutely does not require them. You can simply choose not to enable options trading, not to over-trade (and to turn off price alerts that nudge you to do so), and to use limit orders instead of the default market orders when buying stocks. In fact, you could avoid using Robinhood to buy stocks altogether, and simply use their brokerage account as a way to earn 5% interest while using it to pay off your credit card (though on the other hand, Robinhood could benefit people if it nudges them to do stock investing at all instead of keeping everything in a checking account).

The fact that Robinhood Gold brokerage accounts pay 5% interest on uninvested cash is its other big advantage. You can find savings accounts elsewhere paying 5% or a bit more, but many won’t maintain that rate, and they have transaction limits. Robinhood also pays a 1% bonus on cash transferred in if you keep it there.

Someone moving to the Robinhood ecosystem from a bad setup (paying with cash, or debit cards, or credit cards with no rewards that are paid off from a checking account that earns 0%) could in theory increase their real spending power by 8%+. Even someone in a more common situation (has a 1% rewards card but most of their spending is on things like mortgages that aren’t credit-card-eligible, pays the credit card from a 0% interest checking account but sweeps excess cash to a high-yield savings account paying 4%) could still increase their total spending power 1-3%. Not huge, but a big deal for something that can be set up for less than a days work.

This is now the best single-account setup I know of- assuming you can stay out of their casino. Churning through different accounts can get you a better return, but it is also a lot more work and has its own risks. If you want to up your returns some without the fees or risk of the Robinhood ecosystem, then something like the Citi Double Cash paid from a high-yield (4%+) savings account is probably the way to go.

Disclaimer: I might be wrong about this but if so I am honestly wrong; this post is not sponsored and I’m not even using referral links when I easily could. Still, do your own research and let me know if I’ve missed anything

Update: Robinhood CEO Vlad Tenev did an interview on Invest Like the Best this week where, reading between the lines, he confirms both the positive and negative things I say here. They make most of their money overall on options and active traders; 3% cash back exceeds the interchange fees they get from merchants, but they expect the card to be profitable because some users will carry a balance (and pay interest) and because it will push people to sign up for Gold (so pay fees and perhaps trade more). He notes that there is another card that offers 3% cash back, but it is only available to those with at least $2 million managed by Fidelity.