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Hydroponic Lettuce – The only guide you’ll ever need

Growing your own vegetables is a process that is not only satisfying but is also a job that requires the utmost care and responsibility. And really, when you grow groceries yourself, they somehow taste even better. One among the many house garden plants is lettuce. But a hobby that is even more self – satisfying that growing lettuce conventionally, is growing it hydroponically. Now, it may seem like a process that is time – consuming and complex but if you know the right things to do then growing hydroponic lettuce is very much enjoyable.

Now, just for recollection, Hydroponics is where you grow plants without the aid of soil, by only growing them in nutrient water or moist air. So, hydroponically, you would be growing lettuce. And don’t worry if you think this is a mountainous task, because even if it is, we’re here to make it easier for you.

Hydroponically, lettuce is the easiest plant that you can grow. Especially, for a beginner, staring with lettuce would be a good way to get acquainted with the hydroponic process and to be able to yield good healthy results as lettuce is easy to grow and care for. So what is the process to grow hydroponic lettuce? This is:

A long but simple process.

Step by Step process to grow lettuce hydroponically

With lettuce there’s a small range of variety that you have to pick from. There is Tom Thumb lettuce, Bibb lettuce and Romaine lettuce. But what’s the difference among them? Tom Thumb is preferable if you’re looking for small space consumption. Bibb lettuce, among three, is the easiest one to grow.

So is Romaine lettuce, but it takes a longer while to grow as compared to others.

After you’re done picking the variety of lettuce that you want to grow, the next thing to do is to pick the type of hydroponic system that you want to use.

There are many systems like ebb – flow system, drip system, aeroponic system, NFT system and so on. But for growing lettuce, it is best to pick the water culture system. In this system, the plants float on top of the water, and the roots grow into the water, absorbing all the required nutrients.

It is them important that you pick your medium through which your lettuce will hydroponically grow. There are a wide range of mediums that can be used like coco fibre, pine shavings, sand, rockwool, vermiculite, river rock and others of such kind that can work. It is really up to your requirement as to which one you choose, because all of them are very easily suitable to grow lettuce successfully.

However, rock wool is the most preferred among all because of its porous nature and its sterility. But, you have to take care to not saturate it too much as it can cause root/ stem rot and suffocation of the root.

Another popular option is grow rock. It is capable of holding moisture well and has a great natural pH. It can also be cleaned and reused if you’re hydroponically growing on a small scale, but can prove to be tiring if it’s on a larger scale.

The first step to setting up your system is to set up your water reservoir. This reservoir will hold the necessary water and nutrients that your plants will require.

The surface area of the container that will serve as your reservoir can be whatever you require but make sure the depth is a minimum of 8 inches. We want the roots to be able to properly submerge themselves into the water or else all of it will fail.

In picking out the container, it is recommended to leave out any and every metal option. A metal container will oxidize or corrode and this can prove to be harmful to your plants as it will meddle with their nutrients.

To grow a hydroponic plant, you have to have the plant placed in a net pot. And this net pot will sit in a surface above the water so the only the roots can easily be able to submerge themselves. So get as many net pots as you can.

Take a polystyrene plank and drill it with holes. These holes are what will accommodate the net pots that will hold the plants above the water. The holes must be a minimum of 12 inches apart from each other so that there is enough space for them to grow without competing for space.

Make sure to fill in as many holes as possible to be able to fit in as many net pots as possible.

If you’ve read our previous articles about hydroponic systems then you will know that it is important to have an air pump in a hydroponic system. Lettuce especially would require an air pump to keep the water in the reservoir fresh.

Make sure to choose a good air pump and install it in the reservoir. This pump will make sure that there is dissolved oxygen being circulated in the water and will also make sure to keep the circulating water fresh so as to avoid suffocation.

Now, we finally have to set up the reservoir. So add to it the required amount of water, and then mix in it the hydroponic nutrients that are required. You usually can purchase these nutrients that are already mixed and sold for easy use.

But the nutrients that you mix depend upon the plant that you are growing. Lettuce requires magnesium, potassium and calcium. But depending upon the variety of lettuce that you are growing, the nutrients may also defer.

Make sure to look into nitrogen because some varieties of lettuce may be sensitive to it.

You can’t directly start growing your hydroponic plants in the set – up. They first need to be grown in a small nursery of sorts to provide them with the right kind of environment, to make them stable at first.

For this you can sue egg cartons or plugs and fill them up with your chosen medium and then begin germinating your hydroponic seeds.

How to exactly setup the system to grow hydroponic lettuce

The first step is to properly take care of the seeds you had planted in your small nursery to get them started. Make sure to water them regularly and to place them in a place that has good circulation and is well – lit.

A place with a temperature between 65 F and 80 F would be well – suited. Keep taking care of them in the nursery until they reach a height of 2 inches and have grown up to 4 leaves.

Set up your net pots into the polystyrene plank with the drilled holes. Carefully take the plants from the nursery and place them into the net pots without much tugging.

Fluorescent lighting for lettuce is well – suited. Make sure to provide the lettuce plants with about 10 to 14 hours of fluorescent lighting every day. Lettuce is the type of plants that don’t require much light as other plants would.

And fluorescent light works best as it is of a reasonable cost, especially if you are a beginner and are only trying out. And it is also beneficial to your plants in the way that is requires low power to run on and produces low heat.

It is important to manage the right temperature for your lettuce. They do well in cooler temperatures. It is best to maintain the temperature at around 55 F, at night and at around 75 F, at daytime. Overheating of the lettuce will cause flowering or bolting which will result in a bitter taste.

Keeping the plant’s pH level in check is very important for its nutrient intake. It is best to maintain the pH between 5.5 and 6.5 for best results. Keep checking its pH level frequently with a paper strip test and make sure that it is acidic. PH adjusters can help with levelling the pH in the reservoir. It is best to acquire both down and up pH adjusters.

Tips for taking care of your hydroponic system

Air circulation is very important, especially for hydroponic plants. Because they grow in high levels of moisture, if air around them is not circulated properly, then it may lead to the growth of mildew or bacteria.

And this can prove detrimental to your plants. To have a good air circulation you can install exhaust fans or floor fans or ceiling fans, or even keep a window open. But whatever you do, make sure to see that there is good ventilation.

Damp conditions often lead to the growth of algae. You have to be very careful with hydroponic set – ups because they can easily facilitate algae growth if they are under direct sunlight. Use a shade over your plants to avoid such a scenario.

It is important to keep all insects away. If there are windows, make sure to fit them with mesh and do the same with vents. Lay fly traps around the area to avoid any flying insects.

It is important to look out for mildew that can be caused by water. This can be avoided if you religiously sterilise and thoroughly clean all your equipment that comes in contact with water. Any 2% bleach concoction will get the work done.

You’ve put in the work, and now your lettuce is ready to harvest. That too requires a careful but simple process.

Lettuce takes about 5 to 6 weeks to fully grow. Then you can pick its leaves for consumption. However, lettuce leaves can regenerate themselves in a short amount of time. So it is better to pick only the outer leaves and leave the inner leaves to help growth.

Keep mixing it. Don’t take too many leaves from the same plant at a time. Make sure to fairly pick leaves from all plants so that production is stable.

It’s okay if the plant if fully grown but you don’t want to pick them just yet. But you still have to preserve its freshness for later consumption. In order to do this, move the plants to colder temperature places which will help preserve their freshness up to one month. Nearly freezing conditions are much recommended.


Reviewing this process, you’ll have made the decision for yourselves: hydroponic lettuce is easy to grow and all it requires is a little effort and a little investment. But trust us, the end product will leave you wanting more.

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