How To Prevent Algae In Hydroponics

by Lettuce Be | Last Updated:

In a hydroponic setup, an algae invasion can be a major problem. It adheres to surfaces and can build up. Once it gets a foothold, no system can be safe from it. It can work its way into tubes, into pumps, and put a system out of commission.

It can release a horrible odor when it begins to decompose. However, things get worse when there’s a heavy infestation. You can create a barrier between your growing mediums and this mass of everyday algae species.

Two things will happen when this begins to happen. To begin with, the algae uses up all of the nutrients in the system to grow. Secondly, dissolved oxygen levels are greatly reduced. When this occurs, your plants start suffocating and become weaker, making them more vulnerable to other pathogens like microscopic fungi.

How Does Algae Get Into My Hydroponics System?

algae prevention for hydroponicsAlgae area form of plant life that can live in an aquatic environment. Like plants, they need sunlight, water, and nutrients to grow.

There is a minimum amount of these three basics everywhere the algae population can take hold, making it an incredibly versatile and durable organism. In aquaponic systems, they are hard to prevent and address due to their similar needs to the plants you’re trying to grow. Plants need the same things as you, so you can’t deprive them of their needs.

It is largely due to the versatility of algae as an organism that it can get into your system in the first place. It is possible to think that your system is sterile and sterile during the setup process, only to find that it has been tainted and contaminated by algae.

Algae invade hydroponics systems through microscopic airborne spores. Due to their durability, it can be almost impossible to prevent these spores from getting into your hydroponics system. Growing systems with a sterile environment often confuse beginner growers by wondering how algae can appear. The wind can carry algae spores that latch onto your system. Growers themselves can carry spores without even realizing it.

Algae find the perfect conditions for growth in your system – provided you have set up your system to work well with the plants you want to grow! Algae can be problematic because of this. When they infest your system, they flourish in a short period.

Thus, some growth of algae can be expected when it comes to your system. Keeping a hydroponics system completely algae-free is not possible and so shouldn’t be the goal.

As you are aware that some algae will appear in your system, your focus should be on maintaining its integrity rather than allowing it to overtake it. When algae levels exceed a healthy level, your system will need to be harvested and drastic measures taken before starting another growing session.

Maintaining an acceptable level of algal growth can be achieved by preventing heavy algae growth from getting out of control. Algae control should always take priority over prevention, as it can be difficult to eliminate.

How to Remove Algae from a Hydroponics System

In most cases, the treatment depends on where you are in the process, such as whether you already have stubborn algae or are building a new system. If you want to prevent algae formation from taking hold, it is better to learn what causes algae.

Two things to note are that algae won’t grow on dry surfaces, and you can minimize the effects of algae growth by preventing your hydroponic nutrient solution from getting exposed to as much light as possible. You will cover all of your channels and conduits to prevent light from entering. The same applies to media beds or pots, which you can cover to prevent sunlight from damaging the surface.

When confronted with an algae infestation, hydroponic growers may turn to a commercially available chemical algaecide product. Despite their apparent good nature, they are, in fact, of very little use in controlling an algae infestation.

While algaecide can be useful in preventing algae blooms, it can also damage sensitive root systems if misused or overused. Plants that are small and newly planted into your system are more likely to experience this issue.

Commercial products are ineffective once used, and algae begin to grow again once they fade into the system. This results in a cycle that has no end, and you need more and more of the product.

You’ll want to start by assessing the number of algae in the system. You should determine how it is getting into your system if it is a small amount. Your system could lose light, or some light has found its way into its reservoir.

It is possible to manage the problem with some preventative measures until the end of your plant growth phase if it does not become worse or affect your pump and air stones. You can take the following steps at this point to give your system a thorough cleaning.

You can clean your system by following the steps below. Before starting a new growing cycle, you can do this to remove any algae.

System Sterilization

You need to give your growing room and system a thorough clean owing to how easily a single spore can infiltrate. When you clean your system and find you have no algae spores still on your walls or your lighting, it will be of little use.

Since you will be dealing with your plants directly, your system is much more important. Cleaning the growing medium and pots will be necessary, making sure clay pebbles (Hydroton) stay wet.

Draining the System

Getting rid of your old nutrient mix is the first step. It’s possible that some may not use pumps; in this case, you will have to empty the reservoir manually. If you have a recirculating system, then you have two options for draining your tank.

You can let the water drain naturally if your tank has a drain valve. A run-off area must be set at or below the level of the tank, however. When removing the pump from the tank, make sure all electricity has been isolated.

Connect the female connector to the pump after you remove the outlet pipe. Using the outlet hose, you can now drain to the desired point. By using a pump, you can remove the water rather than draining naturally.

When the pump reaches its lowest point before running dry, you will need to shut it off. The remaining water from both methods will be several inches. Use a bucket and sponge to remove this substance manually.

System Cleaning

You will follow these steps no matter whether you’re dealing with algae or a system clean after every harvest. You can do this to ensure that you have eliminated all traces of algae, pathogens, and bacteria.

There are two chemicals you can use at this point:

Food Grade Hydrogen Peroxide: The concentration should be 35%. Each gallon of water requires 3 milliliters.

Unscented Bleach: Ideally, the ratio is one to one hundred. For every gallon of water, you should add 1.3 oz.

System Components

Your pumps or air stones may not have algae growing on them, but the growing medium and the pots may have traces of it. Hydrogen peroxide is recommended to clean all of these, including pumps. The small components may be soaked in a bleach bath, however. In this case, you’ll need to mix 1:1 and then rinse three times to ensure that all traces have been removed.

Hydroponics: Preventing Algae Growth

To some extent, algae growth is unavoidable in hydroponics systems. Whenever you combine sunlight and nutrient-rich water, you’ll have ideal conditions for algae. Having a nutrient mixture is an unavoidable necessity for algae growth, so cutting down on light exposure is the easiest and most effective method for avoiding uncontrolled growth.

It is best to reduce your reservoir’s exposure to light as much as possible to prevent out-of-control algae growth in your hydroponics system. You can do some things to help with this, but it cannot be easy.

Use Opaque Materials

You can reduce light exposure by using opaque and solid-colored materials whenever possible. Light is effectively blocked from penetrating these system areas, preventing an algae colony from photosynthesizing and growing.

Use A Lightproof Cover

As with step one, the purpose of this step is to prevent algae bloom from ever developing. A reservoir cannot support algae growth if it doesn’t receive light for photosynthetic purposes.

Depending on your setup, there are several ways to cover your water. Using a solid-colored material for crop supports might suffice for smaller rigs. There may be a need for a larger system to have a tarp or plastic cover that has holes cut out for your plants to grow through. However, all other areas should remain covered.

Alternative Options for Preventing Algae Growth

Algae can grow in hydroponic systems if there are any light sources present. However, growers can take a few alternative steps to prevent this nuisance. When applied properly, each of these options can be an effective measure, although their effectiveness varies.

UVC Light

Water filtration systems can be equipped with UVC lights to assist with this process. This light will kill algae. You’ll need to power them as long as you have a computer running. Nevertheless, in situations where amounts of algae are a serious problem, UV light can be helpful.

Grapefruit Seed Extract

A grapefruit seed extract is effective for algae death when used at the correct dosages. As an organic algae control method, it is highly effective against parasites, bacteria, and fungi. Hydroponic systems have proven very effective with it in low doses, and it is not toxic to the plants. It is recommended that you add five to ten drops to a gallon of water in your system. If this is done, you can prevent algae growth.

Barley Straw Rafts

While it is best suited for larger rigs, this solution can also combat algae growth if growing on a large scale. Research indicates that the decomposition of barley straw mats is aerobic and releases a chemical solution that prevents algae growth. In addition to being a tough process, this isn’t ideal for smaller growers. It’s important to ensure that your clean water has dissolved oxygen so that only aerobic decomposition can occur. Currently, barley straw extracts can be purchased to prevent algae growth, but be careful of the number of dead algae, decreasing dissolved oxygen levels.

If you want to keep your system clean and control algae growth, it’s best to limit the light source that comes into your hydroponic solution.

Algae and pH

The algae growth can have a severe impact on the pH levels of your water. That is one area that isn’t addressed. Even though ebb and flow systems are more prone to algae growth, no system is 100% free from it.

Once the conditions are almost perfect for algae to grow, it will get a foothold and cause problems. pH fluctuation is the issue here. In addition to using carbon dioxide to produce photosynthesis, algae also utilize nutrients and light to aid in this process. pH will be at its peak as this period draws to a close.

The situation, however, changes overnight. Whenever algae consume water that contains a boost of oxygen, carbon dioxide is released. Respiration returns this to the water. As a result, carbon dioxide creates a weak acid called carbonic acid, resulting in lowering pH levels.

The more they progress, the more problems they cause. Oxygen depletion can cause a biological oxygen demand. Plants slowly drown from nutrients being locked out, or they can suffer nutrient lockout.

Since you can do nothing to prevent algae accumulation, it is better to anticipate their presence and take precautions to limit their exposure. Following all the above steps ensures that you will be algae-free. It also ensures that your system will perform optimally.

Preventing the same problems repeatedly will eliminate a great deal of cleaning time, even if nothing else.