5 Tips and Tricks for the Blumat Automatic Irrigation System - Happy Hydro

The Blumat Automatic Irrigation System is a miraculous tool for indoor and outdoor growing. Yet getting the install right comes down to perfecting a few small details. Did you set the carrots correctly? Why won't it turn off? Why is there algae growing? If you've installed, but are running into issues, you might need to take advantage of a few expert-tested tips and tricks to Blumat irrigation.

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The Basics of Blumat

Blumat is an Automatic Irrigation System that functions without electricity, batteries, or technical components. The system works through a network of hoses connected to ceramic "carrots" tucked into pots or raised beds. These ceramic pieces automatically maintain ideal moisture levels through a slow-release drip and drip lines.

How is it so simple? Science! According to Blumat, "As the soil dries, a vacuum and hydro-static pressure, coupled with a spring-loaded gating mechanism, pulls water from the mainline. When the soil is sufficiently moist, pressures equalize, and the Tropf Blumat automatically stops taking in water."

For vacation mode or just hands-free gardening, Blumat offers stress-free and affordable irrigation. But, it's a bit finicking for the inexperienced hydrologist. A few tips and tricks can come in handy for dialing they system in.

5 Tips & Tricks to Perfecting Blumat Automatic Irrigation

Tip #1: Prevent Algae Growth Before It Starts

Algae flourishes in warm, nutrient-rich water sources, precisely the environment you may be fostering if you use the Blumat system for timed nutrient release. 

Algae spores are microscopic, and most filtration systems won't work. The best bet is to use bio-safe hydrogen peroxide, in extreme dilution in the reservoir. Blumat irrigation is slow enough that the hydrogen peroxide should have enough time to evaporate before it enters into the system in any real way.

To reduce the risk of algae bloom from the start, reduce exposure to light. Cover the reservoir with a lid, to discourage algae from the get-go.

Tip #2: Getting the Initial Set Up Right

Blumat is simple, but the set up maybe a bit finicky. For example, did you know air bubbles may get caught in the carrots even after an overnight soaking? Use a small pipette, stick within the small wholes in the cap, to remove these secret air bubbles.

Before set up, also consider the makeup of your potting soil. Does it have significant levels of perlite, pebbles, or other problematically 'dry' soil amendments? If in close contact with the carrot, these amendments may trick it into a false reading on moisture levels. To avoid this issue, create a hole for the carrot, and fill with well-watered and perlite-free potting soil. Stick the carrot into this perlite-corrected space.

Tip #3: Fighting Air in a Blumat System

One of the biggest frustrations you may encounter on your Blumat irrigation journey is the fight against pockets of air. Any air within the system will either stop the irrigation completely or create a "Run Away" situation where the drip never shuts off. 

Since this is a gravity-fed system, the primary cause of air within the system is simply a failure to fill the reservoir. Be sure to keep the reservoir topped up at all costs.

There are also air issues at the carrot ends. Let's say if you moved the carrot in the soil, or jostled the pot by mistake, a small pocket could open up between the carrot and the soil mixture. The carrot is no longer physically connected to the soil's moisture level and initiates a continuous run cycle. Avoid moving pots or carrots after install.

Tip #4: Yes, You Can Add Nutrients to Blumat, But Increase the Dilution

Many growers have asked about adding nutrients to create a DIY time-release fertilizing system. Both synthetic and (most) organic liquid fertilizers should work within the Blumat system, so long as the dilution is correct. Most nutrient solutions suggest a dilution that accounts for much of the nutrients to wash out. 

The Blumat system is highly targeted, with minimal water loss. Therefore, you'll want to increase the dilution by an additional 50 to 75 percent (which means fewer nutrients in the water tank).

For larger systems, you may wish to install a circulating pump within the reservoir to avoid having nutrients settle over time. A final suggestion is to always flush the system once or twice with clean water during the grow.

Tip #5: Don't Push it When Adjusting Drip Timing

If you've already set up your Blumat system, you'll have already dialed in the tiny top of each carrot to secure the standing drip at the end of the line. But what if you need to adjust the system later?

Most growers will advise to check back on the first adjustment within 24 hours and reassess one more time in two to three days.If you need to make a correction, adjust by no more than ½ an arrow at a time.

It may take a few days to perfect the irrigation and moisture, but you'll avoid an entire system meltdown. The only time you may need more than ½ an arrow turn, is if you are trying to match two or more carrots to the same adjustment. Never open or close the arrow by more than one full turn in this circumstance.

A Little Practice Makes Perfect with Blumat

Blumat is perhaps one of the most straightforward and non-technical irrigation systems available today. It relies on gravity, and little careful calibration to maintain ideal moisture levels for veggies, cannabis, tropicals, houseplants, and more. 

One of the best parts about joining the growing number of Blumat cultivators is the passionate and supportive community. If you have additional questions about working out the kinks within a Blumat system, check out the grower forums and detailed Q&As for more troubleshooting.

Author | Chris McDonald

With two decades of expertise, Chris leads Happy Hydro in redefining sustainable gardening and delights in backpacking adventures, mind-expanding journeys, and creating memories with his loved ones.




Has anyone found a way to covert from the 8mm tubing (that is hard to find) to the 1/4" irrigation tubing that is easily sourced in the US and inexpensive?

In our situation we have lots of left over 1/4" from previous irrigation systems.

Also found out the hard way that this 8mm tubing is too loose a fit on the carrot


Polly Schrag

Polly Schrag

We used the Blumat system this year for the first time. I’m not fond of the algae growth on the top of the soil in the plant cells. Is there anything that I can do to minimize this issue. Also, it’s installed in a hobby greenhouse. What steps do I take to clean and store for next year. Thank you.

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