What What Is Hydroponic Drip System And How Does This Work

Why is hydroponics a whole world and not just a gardening technique? Well, to start with, hydroponic gardeners are a bit like sci-fi “geeks”, very much enthralled by this “high tech” field of farming.

But there is more; there are a lot of scientific studies on it; it is so revolutionary that it can change the future of the planet…

Last, but not least, there are many hydroponic techniques, from deep water culture, ebb and flow, the wick system, aeroponics and finally a favorite by hydroponic gardeners: the drip system.

But what is drip system hydroponics?

Drip system is a hydroponic method where the roots of the plants are in a growing medium and not immersed in the nutrient solution (water and nutrients); instead, the solution is pumped to them regularly thanks to irrigation pipes.

This guide will give you everything you need to know about the drip system of hydroponics how does a hydroponic drip system work, pros and cons and how to setup your own drip system.

What Is The Drip Irrigation System?

In a drip system you will keep the nutrient solution in a reservoir (or sump tank) which is separate from the grow tank, where you plants will live.

Then, with a system of water pipes, hoses and a pump, you will bring the nutrient solution to the roots of the plants in drips.

There will be a hole, dripper or nozzle in the hose at the base of each plant that allows to irrigate each individual specimen evenly. Each plant will get the same amount of nutrient solution.

The plants will be in mesh pots with a growing medium in them (like expanded clay) and this will allow the nutrient solution not only to spread more evenly to the roots (by trickling down through the pebbles), but also to be available to the roots for long, as it gets absorbed by the growing medium and then released to the roots.

The excess solution is then collected at the bottom of the grow tank and drained back into the sump tank.

This is the key principle of the drip system.

Nutrients, Water And Aeration In The Hydroponic Drip System

To understand the key dynamics of hydroponics you need to appreciate how each system ears with the roots’ need for water, nutrients and aeration.

In fact, one of the big problems with early hydroponic methods was how to bring oxygen to the roots.

Plants’ roots, you may know, do not only absorb water and nutrients; this was solved early on by mixing the right amount of nutrients to water, and getting what we all call now “the nutrient solution”.

Hydroponic pioneers were scratching their heads trying to come up with a good way of giving air to the roots.

First came air pumps, a bit like the ones you use in aquariums. But there is a problem here; an air pump in a deep water culture system can only aerate the water to a point.

What is more, if you put the air stone on one side of the grow tank, the plants on the other end will get no oxygen.

If you put it in the middle you will get better results, but still the plants in the center of the grow tank will get much more air than those around the edges.

A perfect solution to this problem came from rediscovering an ancient irrigation technique already used in ancient China and new technological developments in the 50s:

Drip irrigation was already known in China in the First Century BCE.
In the 1950s, however, two big innovations combined with this: the spreading of greenhouse gardening and plastic, which made pipes and hoses cheap and, above all, flexible and easy to cut and adapt.
Hydroponic gardeners thought well to use a drip irrigation system with plastic pipes to develop what we now know as hydroponic drip irrigation, or drip system.

Using drip irrigation means that the roots will be surrounded by air primarily, and not immersed in the solution, which gives perfect aeration, as in fact, roots need lots of oxygen.

How Does The Drip System Work?

The basic idea of the hydroponic drip irrigation system is fairly easy. There are a few ways in which this can be varied, but let’s look at a standard system to start with:

You will mix water and nutrients in the reservoir.
The pump will fetch the nutrient solution from the reservoir and send it into a system of pipes and hoses.
The hoses have a hole or nozzle for each plant, so they will drip the nutrient solution individually to them.
The plants’ roots are in a mesh pot suspended in a deeper grow tank.
In the mesh pot there will be an inert growing medium (expanded clay, coconut coir, vermiculite or even rockwool). This will fill with the nutrient solution and release it slowly to the plants.
The excess nutrient solution drops to the bottom of the grow tank and it is then drained back into the reservoir.

From here, you will then be able to start the cycle again. As you can see, it is very efficient when it comes to using the nutrient solution.

What Elements (Or Parts) Do You Need In A Drip Irrigation System?

On the whole, you won’t need much more than what is necessary for most hydroponic systems, mainly a few more pipes and hoses… And they are as cheap as dirt if you excuse me the pun:

A reservoir or sump tank; with the drip system, you can save space and money on the size of the tank compared to, for example, an ebb and flow or deep water culture system. Why? You will not need to have the same volume of nutrient solution in your reservoir as you need to fill the grow tank, as you do with these two other methods.
A water pump; necessary if you want an active system and not a small passive one, the pump for a drip system does not need to be particularly strong though; this is again because it will only send a small amount of water through the pipes at any time. This is, unless you want to use a high pressure system, which we will see in a moment.
Water pipes, hoses and fittings; these, as we said, are very cheap nowadays. We will come back to these later on, as managing them is one of the key skills you will need for this hydroponic system.
Mesh pots; with some systems you may even avoid mesh pots (often with the Kratky method and aeroponics); with the drip water system you must use mesh pots. On the other hand, they are very cheap indeed.
A growing medium; not all hydroponic systems need a grow medium; actually all systems can work without, even if using one is better, apart from one: with the drip system you must use a growing medium.

This Is What Is What You Absolutely Need, But There Are A Few Other Elements You Will Want To Add:

An air pump; you can use an air pump to provide extra oxygenation to your nutrient solution; if you do, place the air stone in the center of your reservoir.
A timer; using a timer will save you a lot of time and work… In fact you will not need to irrigate your plants continuously, but only in cycles. This is because the growing medium will hold onto nutrients and water and release them gradually. If you just set the timer, it will run the pump for you. At night too, but remember, roots need less water and nutrients than during the day.
A thermometer to keep an eye on the water temperature.
An electrical conductivity meter, to check that the EC is within the range your crop needs.
A pH meter to make sure the nutrient has the right acidity level.

Of Course, If Your Garden Is Indoors You May Need LED Grow Lights As Well.

It may look like a lot, but you can literally build a fair size garden with between 50 and 100 dollars. The most expensive part will be your pump in most cases, and you can get a good one for less than 50 dollars, but there are much cheaper ones (down to less than 10 dollars) if you only want a small garden that fits in your kitchen or on your small balcony.

Variations Of The Drip System

Did I say that hydroponics is a whole world? Like with most hydroponic methods, even the drip irrigation system has many variations and a range of solution from the simplest to the high tech and futuristic.

There are several adaptations of the key concept in fact, including:

Passive hydroponic drip irrigation (which only uses gravity).
Active hydroponic drip irrigation (which uses a pump).
Low pressure hydroponic drip irrigation (which uses, you guessed, low pasture).
High pressure hydroponic drip irrigation (where the pump sends the nutrient solution to the plants at high pressure).
In a Dutch bucket system, instead of having a single grow tray with many plants in individual mesh pots within it, you use individual buckets, each functioning as a grow tank. The bucket is made of an external (usually dark plastic) container and an internal and smaller mesh pot. These can also have a lid.

To be fully correct, even aeroponics is in fact a development of the drip system; however, it is regarded as a separate method for a few reasons:

The nutrient solution is sprayed as droplets, not dripped, this is the fundamental difference.
Aeroponics does not use a growing medium at all, as it would be a barrier between the roots and the nutrient solution when sprayed.

Passive And Active Drip Irrigation Systems

You may have seen drip irrigation used also in soil gardening; it is becoming very common in hot places.

Why? It saves water, it irrigates very homogeneously, it discourages weed growth and finally it prevents water evaporation.

But small soil gardens often use what is known as passive drip irrigation, while there is also active drip irrigation. What is the difference though?

In passive drip irrigation you place the reservoir above the plants you want to irrigate; this makes sure that gravity will bring the water or nutrient solution from it to your crop. Water simply falls down and nourishes your crops.
In active drip irrigation you will use a pump to bring water to your plants. This allows you to put the reservoir anywhere you want, even below the plants.

Which Drip Irrigation System Is Better For Hydroponics, Passive Or Active?

You can use a passive drip irrigation system for your hydroponic garden, and some people do.

This may work well on condition that you have a small garden and you will also save some money on your electricity bills as you will not need a pump.

However, there are two major problems; a passive system is not suitable for big gardens as it cannot guarantee that all the plants will receive an adequate quantity of nutrient solution.

What is more, you will not be able to collect the excess solution.

This is why most hydroponic gardeners by far prefer an active irrigation drip hydroponic system; this way, you have full control on the distribution of the nutrient solution and you can put the reservoir under the grow tank to collect the excess solution through a hole at the bottom or even a pipe.

This Way, The Solution Is Irrigated Actively And Collected Passively.

Low Pressure Hydroponic Drip System

This is when the pump you use is only sending the water through the pipes at slow speed and without putting pressure into the pipes themselves.

Even a passive drip irrigation system can be called “low pressure”; that is, unless your reservoir is so high up that the gravity puts lots of pressure on the nutrient solution.

In a low pressure system, the nutrient solution simply travels through the pipes at slow speed and without fully filling the pipes usually.

This system is not optimal with big gardens, but you will still get excellent results. In fact:

It is cheap, because you will not need much energy to run your water pump.
The risk of spillage and pipes breaking is low, as you will not put pressure on them.
It can be run with a basic plumbing work that does not require special skills.
It is ideal for small and non professional gardens.
You can even run it without drippers or nozzles; a simple hole in the pipe will do in most cases.
You can use very cheap and thin drip irrigation tape will do; this is like a plastic tape with a hole inside, a bit like an inflatable straw, which fills with water when you irrigate. It’s so light, flexible and easy to use that it’s quickly becoming a favorite with both soil and hydroponic gardeners all over the world.

High Pressure Hydroponic Irrigation System

In this case, the nutrient solution is pressed into the pipes, pushing out all the air first and creating high pressure.

If you have seen sprinklers on lawns, you will have witnessed a high pressure drip system in action.

With this system, you can reach optimal levels and uniformity of irrigation even over a large area.

This makes it ideal if you are “thinking big” and professional. But for a small, home garden, this system has some great disadvantages:

It will cost far more in energy than a low pressure drip system.
It requires good plumbing skills, in fact, for large gardens you may need a professional.
You will need high quality plumbing parts, like pipes and fittings.
You will need to use nozzles sprinklers and even valves in your piping system.
It requires constant maintenance and checking.
It is more at risk of spillage and breaking.

Thus, unless you want to set up a large professional hydroponic garden, your best choice is to go easy and safe with a low pressure drip irrigation system.

The Dutch Bucket System

This is an extraordinary method, where you keep the roots of your plants in individual buckets working as grow tanks, as we have seen.

By far the best system to grow even small trees, like lemons, oranges, fig trees, pear trees etc.

It is sometimes considered its own method, but because the principle is exactly the same as that of the drip irrigation system, I think it falls clearly within this wider method.

The Dutch bucket system has great advantages:

It creates a consistent and steady microclimate for the roots, with regular temperature and humidity within the buckets.
It prevents algae growth, as the buckets are impenetrable to light rays.
It lowers the chances of disease spreading from plant to plant through the roots.
It prevents water evaporation in the growing tank (bucket), which comes in particularly handy on hot and dry summer days.
It is, as we said, ideal for big plants and even trees.

On the other hand though, it is more expensive than a standard drip system. Still, if you want to grow mangos, papayas, bananas (yes you can!) and other big plants or fruit trees, this is by far your best option.

The Best Plants For A Drip Hydroponic System

Of all the hydroponic systems developed so far, the drip system is one of the most flexible systems.

Apart from the fact that it adapts even to big trees, as we have seen already, it is also suitable for plants that like to keep “their feet dry”, like Mediterranean or tropical and subtropical plants.

You cannot, for example, grow lavender in a deep water culture system; this plant does not stand humidity on its aerial part (stem, leaves and flowers) and it does not like too much moisture around its roots.

So, the drip system allows you provide nutrients with plenty of air and limited moisture.

Other plants do not like stagnant water; for these, you can only use ebb and flow, aeroponics or a drip irrigation system. Watercress is a prime example of this.

For root vegetables, if you use any system that keeps the roots permanently in the water solution you will risk that when you harvest your carrots, turnips or potatoes, you will throw them straight into the compost heap as they have rotted away. On the other hand, a drip system will be fine for them.

There are many plants that suit a drip system, in fact, almost all the plants you can grow hydroponically, if not actually all of them. However, if you want a “best pick” list…

All small trees and fruit plants, like peaches, apples, etc.
Tomatoes
Lettuce
Strawberries
Leeks, onions and garlic
Egg plant, peppers and zucchini
Melons
Peas and green beans
Herbs in general

As you can see, you can pick vegetables and fruits from many different categories if you use a drip system.

Why Choose A Hydroponic Drip System?

I must admit that this is one of my favorite hydroponic systems. There are many reasons why you may choose one in fact:

It is very flexible; it works well for towers, vertical gardens, and even oddly shaped gardens. Hoses are easy to bend, and if you use individual Dutch buckets, even small ones, you can even fit the odd plant in a corner with just a pipe coming from a centralized reservoir.
It is suitable for most plants. This is no small advantage if you want the chance to change your crops over time.
It provides excellent root aeration. I cannot stress enough the importance of this element when choosing a hydroponic system.
You can easily adapt it to tailor your plants’ individual needs. Even using a centralized reservoir, you can irrigate differently using different pipe sizes, faucets etc.
It provides a regular quantity of nutrient solution to all plants.
It is fairly easy to manage.
It optimizes water usage, especially compared with other systems.
It avoids large algae growth, which is common with deep water culture and ebb and flow.
It does not have stagnant water, which is on the whole bad for your plants and often spreads disease.
It is easy to set up yourself.

I think it makes for a nice list of points in favor of choosing a drip system.

What Are The Disadvantages Of A Hydroponic Drip System?

No hydroponic method comes without some disadvantages; and the drip irrigation system is no exception. Still, I find that the problems we face with drip irrigation are never big enough to put people off using it and always easily solved:

The main problem is with the nutrient solution pH; while on the one hand the drip system recycles excess solution (which is good), when it goes back into the reservoir it can alter its pH. The solution is to keep a close eye on the pH in the reservoir.
The nutrient solution pH also affects the electrical conductivity in turn; as you will use this measurement to decide if your solution has run out of nutrients and needs changing, it is yet another reason why you should keep a close eye on the pH.
Because it has many pipes, occasional spillage is to be expected. Water does push and move these pipes, and at times they come off or leak. Still, this is not a huge problem as you can easily fix them.
You will need to know a few plumbing tricks which gardeners all over the world use all the time…

On the whole, as you can see, the advantages far outweigh the disadvantages.

How To Set Up A Hydroponic Drip System For Indoor Gardening

Now, let’s see how you can set up a standard hydroponic drip system at home, even fitting into a small and unused corner of your kitchen for example.

You will need all the elements and parts we mentioned before: a grow tank, a reservoir, pipes, a water pump and possibly also the pH and EC meter, a thermometer, a timer and an air pump, just to remind you.

In terms of plumbing, you will need pipes, hoses, fittings (90 degree elbows, caps, barbs, hose clamps etc.) I would suggest you plan your plumbing ahead, so you will know what you need.

Start with the reservoir; place it under where you will put the grow thank.
Now, put the stone of the air pump if you want to use one into the reservoir, better if in the middle.
Attach a pipe long enough to reach the reservoir to the inlet of the water pump. You can use an adjustable screw band hose clamp to fasten it.
Place the end of the pipe into the reservoir, making sure it fetches deep, near the bottom.
Connect the timer to your water pump, this is only if it does not have one already, of course.
Now you can clamp the thermometer, EC meter and pH reader to the side of the reservoir.
You can now connect the main pipe to the outlet of the water pump.
Now, it is best if you attach a tea fitting (it looks like a T) a 90 degree elbow (it looks like an L) here; the reason is that if you want to change the layout of your piping system, it is better if you do not change it back at the pump.
Now, attach one or two (if L or T junction) even smaller pipes and put caps at the end.
You can now pierce a hole for every irrigation hose you want to have. Each hose will correspond to a row of plants, like in a normal soil garden. Make the holes of the right size to insert the barbs you want to use.
Insert the barbs; you should do it by screwing it and not pushing it like the cork of a wine bottle.
You can now attach all the hoses to the barbs. Fasten them well with adjustable screw band hose clamps.
Now, place the grow tank on top of the reservoir and place a hole in the bottom.
Place the different mesh pots; make sure that there is enough room underneath them so that you can collect excess nutrient solution.
Rinse the growing medium and fill the mesh pots with it.
Stretch the hoses along the mesh pots, in rows.
Place a hole in the hoses for each mesh pot. Irrigation tapes often come with strips, a bit like band aids, that you can strip off at your convenience. You can then add a dropper or nozzle if you want, but it may not be necessary.

Now you are almost ready to plant, but you need a little trick first.

How Do You Close Hoses At The End? There Are Two Ways:

If it is an irrigation tape, just cut it about 10 to 15 inches past the last plant and tie it with a simple knot.
If it is a PVC hose, cut it about 10 inches from the last plant or even more. Then cut an inch wide ring from the very end. Fold the hose onto itself and use the ring to fasten it.

Very importantly, only connect the pump, timer etc. and start it only after you have mixed in the solution. Do not get your pump to dry run.

You can now plant and set the timer!

All this is, of course if you want to build your garden yourself, and you like to spend a good afternoon DYIing with your kids…

Otherwise you can just buy a kit! They are quite affordable indeed.

How often should you irrigate your plants?

This very much depends on a few factors:

The type of plants, and how much nutrients and especially water they want.
The weather, heat and humidity in particular.
Which drip system you use (if the grow tank is open, a Dutch bucket, high or low pressure, the size of the hoses etc.)
The type of growing medium, some hold the nutrient solution longer than others.

This may vary a lot, from 15 minute cycles after a 15 minute pause (15’ on and 15’ off) to a cycle every 3 to 5 hours.

Remember that at night you should reduce or in some cases even suspend cycles, in case it is humid enough. Plants have a different metabolism at night, but they still breathe through their roots.

You will soon get used to what your system, plants and place need. But there’s a little “trick of the trade” I want to share with you…

Plant an adult tomato and keep an eye on it; when the top leaves droop, it means that it needs water and of course, nutrients.

You can use it as a living “gauge” get to know your garden’s irrigation needs.

Conclusion

Now you have all the facts, I think we can agree that a hydroponic drip irrigation system must be very high up on the chart of your favorite systems.

It does have a few small disadvantages, but it is very functional and economical; it provides perfect watering, nutrition and aeration to the roots of your plants; it is adaptable to any situation or garden size; it is suitable for virtually every crop and it can easily be changed and adjusted.

This explains why the drip system has quickly become a favorite with hydroponic gardeners and growers, and why, even if you don’t fancy a kit, and you want to build your own.

It could only mean spending a fun day and some quality time with your kids, doing something useful while learning some handy skills and a lot about the life of these wonderful companions of ours on this planet we so much need and love: plants…

Written By

Adriano Bulla

After many years as an academic in London, Adriano Bulla became a writer, publishing books like A History of Gardening, Organic Gardening and Elements of Garden Design; he then decided to become a gardener, following his childhood dream, and has been following his dream writing and gardening professionally in Southern Europe, where he has specialized in new and innovative organic gardening fields and techniques, like permaculture, regenerative agriculture, food forests and hydroponics.