How to Deal with Algae in New Aquariums

Today, we look at a common yet often misunderstood approach to algae on plants in newly planted tanks, such as the case in the picture above, where a hazy carpet of hair algae covers the newly planted Utricularia graminifolia.

Another example below:Algae growth is a common issue in newly established aquariums, particularly for hobbyists setting up a tank for the first time. Understanding the dynamics of algae growth and the measures to control it can help maintain a healthy and visually appealing aquarium. This guide delves into the causes, preventive measures, and effective control strategies for dealing with algae in the new aquariums.

Understanding Algae on Aquatic Plants

It is expected to see algae attaching to plants in newly planted tanks, such as hair algae. This often appears as a hazy carpet over newly planted species like Utricularia graminifolia. When algae are preferentially attached to plants rather than hardscape, it is usually a sign that the plants are struggling. Healthy, robust plants are typically more resilient to algae. 

Causes of Algae in New Tanks

Nutrient Imbalance

Algae thrive on excess nutrients, such as nitrates and phosphates, often resulting from overfeeding, decaying organic matter, or an imbalance in the nutrient supply. These conditions provide an ideal environment for algae to flourish. 

Lighting Issues

Improper lighting, both in duration and intensity, can accelerate algae growth. Algae require light for photosynthesis, and too much light or the wrong type of light can exacerbate their growth. 

Plant Adaptation

In a new tank, plants are still adapting to the environment. This adaptation phase can lead to an initial bout of algae, particularly filamentous varieties like hair or thread algae. During this period, plants channel energy towards growing new, algae-free leaves, while older leaves may become algae-infested.

You are Not Wrong

Fundamentally, when algae preferentially attaches to plants (rather than hardscape), it is a sign that the plants are struggling.
Strong, healthy plants are very resilient to algae.
In a new tank (< 3 months old), it is common for plants to get an initial bout of algae.
Often these are of the filamentous variety (hair / thread / stag horn etc.)
Such algae may suddenly appear even if the plants were initially algae free in the first 1 or 2 weeks after planting.

This can be triggered by many causes, but it is fundamentally linked to the plants still adapting to the tank environment.

Plants adapt by channeling their energy towards new leaves, so the newest leaves often remain algae-free while the older leaves get attacked by algae, as seen in the picture of the Monte Carlo below:

What Not to Do?

Avoid Drastic Changes

Many hobbyists, noticing algae growth, might drastically change the tank environment, such as altering nutrient levels, adjusting water flow, or adding CO2. However, these changes can further stress the plants and exacerbate the problem. Introducing algicides or DIY algae treatments can also be counterproductive, as they can disrupt the tank's balance and harm beneficial microorganisms.

Effective Algae Control Measures

Stabilize the Environment

The best approach for dealing with algae in new tanks is to maintain a stable environment. This means avoiding frequent changes in lighting, nutrients, and water flow. Stability allows plants to adapt and grow strong, reducing the chances of algae taking hold.

Achieving Critical Planted Mass

Ensure that at least 70% of the substrate is covered with plants. This critical mass helps in nutrient uptake, reducing the available nutrients for algae.

Proper Plant Selection

Select plants suitable for your tank's environment, considering light, CO2 levels, and water hardness. Different plants have varying needs, and ensuring they match the tank conditions can help them thrive and outcompete algae.

In other words, the instinct to 'adjust something' is understandable but often counter-productive. 

What Should I Do?

• If you have already ‘shaken the tank’ a little too much, the fastest path to recovery is probably (unfortunately) a reset. Remove the algae infested plants, and put in a new community. This is because while plants generally recover, badly algae infested plants that have been in unstable environments can take many weeks, even months to recover. This is too long for most hobbyists to stomach.
  
  When putting in new plants, it is important to attain ‘critical planted mass’. A rule of thumb is to cover at least 70% of the substrate with plants. 
  
  
• Review plant choice. Do your plants fit the tank environment in the first place? Do they have enough light and CO2 for the selected species?
  
  Many plants look similar, but have vastly different needs, as we compare, for instance, HC Cuba and Monte Carlo.
  Are you trying to grow softwater plants in hardwater (or vice versa?)
  
  
• If the plants fit the environment, the best but hardest thing to do ( as we are all impatient) is to simply keep things stable (don’t fiddle around with changes in light, nutrition, flow) and give room for nature to work its magic.
  For a tank with CO2 injection, it often takes 2-3 weeks for new plants to adapt. For tanks without CO2 injection, it takes much longer- 45 to 70 days is common and natural (as the pace of growth is 5X- 10X slower without injected CO2. No- 'liquid CO2 doesn't count).
  This is a very long time- and the key reason why tanks without CO2 injection are in many way harder for beginners. It is like trying to build muscle with limited protein. Possible, but much harder. 
  
  Observe new shoots- if they are healthy and algae free, it is a sign that the plants are progressing on the right path.
  
  As a rule, algae-infested leaves do not become un-infested.
  Deteriorating leaves do not 'heal', unlike our skin.
  Plants focus on growing new leaves instead. 
  
  For stem plants, we would simply replant the healthy tops and discard the algae-infested lower portions after the healthy tops grow tall.

What about Dosing Anti-Algae Products?

If you have a Dutch-style tank, this is generally unnecessary, as fast-growers (with the right tank setup) almost always outcompete algae after a few weeks. Then, it is simply a matter of replanting the healthy tops and discarding the algae-infected older leaves/ stems.
However, spot-doing something like APT FIX would be helpful for slow growers such as Bucephalandra, Anubias, Alternanthera reineckii etc. as their old leaves can often recover (one of the secret advantages of slow growers) and new leaves take many days, even weeks, to develop.

Above: It is also fine to spot-dose on hardscape / wood to remove algae. We avoid pouring anti-algae agents directly into the tank because they are typically effective only at higher concentrations, and at those levels, we risk damaging the fragile and important microbial community that is a important part of achieving tank stability.

Diatoms can arise from planting before the tank was fully cycled.
While they look nasty, experienced aquarists know that they are actually rather benign and disappear quickly after the tank stabilises.
In general we should not need to use use algae-treatment products on Diatoms.

Conclusion

Dealing with algae in new aquariums requires patience, consistency, and a balanced approach. By stabilizing the tank environment, selecting appropriate plants, and implementing both manual and biological controls, hobbyists can effectively manage algae growth and maintain a thriving aquatic ecosystem.