How to Start Seeds for Hydroponics? (Guide to Germinate Seeds)

So you have grown fond of Hydroponics and have begun planning to go for hydroponics gardening. But how about starting some seeds for hydroponics? How about learning the basics of how to start seeds for hydroponics? 

Quick Response

For successful seed germination in hydroponics, you need an adequate and good-quality medium that provides consistent moisture. It is advisable to put the seeds in distilled water for at least one hour is highly recommended to get them moist thoroughly. Once the medium has got sufficiently moist, place the seeds into it.

How to Germinate Hydroponic Seedlings – A Step by Step Guide

If you want to germinate hydroponics seeds, you need to have a proper combination of three things – moisture, bright light, and warmth. Seeds invariably need these environments for proper germination into seedlings. This process will require the proper environment for proper and effective germination. 

Remember that you should remove the seedlings as soon as you witness the parts of the plant emerging from the seed part. 

Medium required for starting seeds in Hydroponics

You have many options for medium for seeds germination. It would be advisable to use the ones that best meet your individual preferences and expectations. 

Coco peat 

The cocopeat is the by-product of the Coco growing industry.  Coco peat is widely available in the form of large bricks. It is made from the coir fibres and they are washed and heat treated. One of the huge advantages that you stand to get with the cocopeat would include  the natural rooting hormones that it is made of. 


The cocopeat comes with antifungal properties which further make it a formidable pick for fighting the damage to the seeds. One of the huge advantages that you stand to gain with the cocopeat is that it can hold up to 8 to 9 times of its own weight in water. 

Some benefits that you stand to gain with the cocopeat would include:

  • It can store and release nutrients into the plants for extended periods
  • The finest oxygenation properties further make it a great option 
  • Slightly acidic pH levels.

Coco coir

The Coco coir is capable of retaining water and thus you do not need to worry about over-watering or under-watering your seeds or plants. In case you are looking for something really organic, coco coir is something that would make the best pick. 

coco coir

It follows the same procedure as coco peat in its manufacturing or production. It is comparable to the “hair” that you would find in the coconut husks. It does offer you the same properties as the cocopeat and can double up as the perfect growing medium for your needs in hydroponics seed starting. 

Some features offered by the  Coco Coir can include:

  • You can either use them as starter cubes or as later cubes based on your individual needs 
  • It is quite commonly used in the passive hydroponics systems. 
  • It may not be clean though.


Unlike the coco peat and coco coir, Rockwool is not natural and is manufactured through the use of chemicals. It is made by heating and spinning the special silica like materials and then converting them into fine threads. 

Rockwool cubes come with pre-drilled holes and provide enough space for younger roots to emerge. They also provide the best possible drainage solutions. This is helpful in avoiding the excess moisture. This can also be a great option to help avoid the possibility of root rot. 

Some features of Rockwool cubes can include:

  • It provides the perfect level of oxygen to the plants. 
  • It is completely pH neutral.


In case you are using rockwool or rooter plugs, you would need netcups for germinating the seeds. You may also look for the specially crafted trays for the purpose. 

A Container/Railway

Since you are beginning with a huge number of seeds, you would need boxes or trays for holding the seeds and the subsequent seedlings. The containers with a depth of around 4 to  6 inches would be preferable. 

Humidity Dome

A humidity dome is an essential element for starting the  seeds hydroponically. You should place it at the level surface and make sure that it is at least 12 inches away from the tray. It should also have enough airflow. 

Heating mat

The heating mat is another important option to be considered for providing warmth and heat during the process of germination. This will ensure a good and healthy germination process that yields better seedlings. 

Grow lights 

The grow lights can be a great option if you are germinating the seeds indoors. There are different types of grow lights that you would ideally use in hydroponics. A few good examples include HID grow lights, LED lighting, and CFLs. You can even consider checking out the Seed Starter Kit with Grow Light which can provide you a simple-to-use option. 

Recommended Buying 

Seed starter kit with grow lights 

Instead of opting for the DIY option for your hydroponics garden, how about checking out the best durable tray with a 60 cell seed starting options. It also comes with its own humidity dome. It your perfect pick for the indoor seed starter kit with light. 

The package includes:

  • Humidity dome: for controlling humidity
  • 60 cell seeding tray: this is for starting seed 
  • Seeding tray: for collecting water
  • Grow lights: effective for seed germination, plant growth and blooming 
  • Bracket: for powerful attachments

A few features would include:

  • Strong plastic construction
  • Adjustable moisture level 
  • An excellent humidity control 
  • A perfect fit for fixing tightly


How to Start Seeds for Hydroponics?

Having found out the right materials for starting seeds in hydroponics, let us now check out the step-by-step guide on how to start seeds in hydroponics. 

The step-by-step guide on how to start hydroponic seedlings can include

Step 1: Prepare the growing medium 

Irrespective of whether you are using cocopeat, coco coir or rockwool, you will need to soak them in the water for preparing them. If you are using rockwool, make sure that you need to wash it in the mixture of vinegar and water. This is because it consists of a high pH value. 

Make sure that the cubes are  moist by keeping them in fresh water for around an hour. 

Step 2: Place the seeds 

You cannot guarantee that every seed you have started with will germinate. You will thus need to place a few seeds in every cube of the starter medium. You can even place the seeds in a Ziploc bag and seal them. You can then place the bag in a dark corner for 2 to 5 days for allowing them to germinate. 

Once the seeds have germinated, you can place them in the grow tray. Place them in the individual net cups inside your grow tray. 

Step 3: Add water and nutrients

Fill the bottom of the tray with a mixture of water and a  lower concentration of hydroponic nutrients. The water level should be maintained at such levels that it simply submerges half an inch of your starter cubes. 

Keep monitoring the  water level. If you find it going down, you can add more water and nutrients. 

Step 4: Grow lights and hardening

If you are growing the seeds indoors, it is advisable to use some grow lights for a more efficient performance. This can be helpful in getting healthy and strong seedlings. It would be a good idea to use the grow lights for 10 to 12 hours a day. 

As the seedlings grow further, the need for light increases. The light intensity of the plant grows  further as the true leaves begin to appear. 

Step 5: Transplant 

The next step involves transplanting the seedlings into your hydroponics system. Seeds generally germinate within 2 to 3 weeks and once they develop true leaves, you will need to transplant them into the hydroponics system. It would be advisable to check for the development of roots at the bottom of your medium. 

While transplanting the seedlings may appear to be an easy task, you need to be careful with it. The plants, especially seedlings are likely to experience the transplant shock. It can be due to the removal from the growing medium and also exposure to the new environment. The seedlings may take a while until they get used to the new environment. 

Why Are Seeds Better Than Seedlings in Hydroponics?

Starting the hydroponics plants right from seedlings may appear to be a better option and it would take less time in making them grow into mature plants in a shorter time span. But, buying seeds from the stores is a good idea than buying the seedlings. This has obvious reasons.

Starting with seeds will ensure that you can choose a variety of seeds and plants and you will ensure that they will grow best in your grow space. In fact, growing your plants from seeds will ensure that you have access to healthy plants. 

Since the plants bought from stores may have been grown under sterile conditions which may be quite unnatural. That would perhaps make them not suitable for the natural surroundings where they may need to face and fight pests and diseases. 

Also Read:

Why Haven’t all My Seedlings Survived?

There can be several reasons as to why your seeds have not germinated. It is for sure that not all seeds will germinate, but there cannot be a reason assigned for the same. Depending on the plants that you have chosen, there may be several issues or differences that may make a plant difficult to survive. 

A few of the reasons why a few seeds may not germinate or a few seedlings may not survive can be due to the following reasons:

  • Dried out media: Seeds need a moist environment to germinate and grow. If your media dries out, it can result in the seedlings dying or  seeds failing to germinate. 
  • Retaining high humidity: The seeds need to retain moisture. An upturned tray or a humidity dome would be a good option to help you retain the moisture. Lack of humidity can be one of the reasons why a few seeds may fail to germinate
  • Too wet conditions: If you tend to overwater the plants, or your rockwool gets too wet, this can result in getting the seeds rotting. Instead of pouring water, make sure that you are spraying water. 
  • Do not overfeed: The nutrients in excess can be yet another reason for the seeds failing to germinate. EC of the water should be in the range of 0.8 to 1.2.

Frequently Asked Questions

Can you plant seeds directly into a hydroponic system?

No, you cannot plant the seeds directly into the hydroponics system. You will need to germinate the seeds through the use of good germination techniques. 

What is the best medium to germinate seeds for hydroponics?

The growing medium for germinating the seeds is available aplenty. You can use several options that would include Rockwool, peat moss, or coco coir. All of them work effectively and you can use them interchangeably as per your preferences. 

Can you use cocopeat as a medium for hydroponics?

Cocopeat is an excellent and perfect means for seed germination in hydroponics. It is very lightweight and that would makes it very easy and simple to transport. It is also a good absorbent.

The Concluding Thoughts

Starting the seeds hydroponically can be one of the most practical solutions. Irrespective of whether you are an expert or a beginner, you would find the ways to start seeds for hydroponics a great option. The tips and ideas shared above should perhaps prove to be quite effective in letting you pick the best options in growing your plants. 


Nikita is a Succulent lover. She really enjoys planting and nourishing them. She loves to share information about various Succulents on this blog to aware people more about these awesome plants.

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