Troubleshooting with George Farmer

1) Why can’t I grow aquarium plants?


This is probably the most common complaint for aquarium hobbyists and the solution can be complex. However, by following some simple steps you should be able to achieve success with your plants.

  1. Buy fresh and healthy aquarium plants. Ensure they are aquatic plants. Some retailers sell non-aquatic plants labelled for aquarium use. Tropica is a trusted brand that don’t stock non-aquatic plants.
  2. Ensure you have sufficient lighting for your chosen plant. Research the species to see how demanding it is. Start off with easy plants to give you the best chance of success. Check out our article on “How to Aquascape Part 3 - Planting” for more info.
  3. Use a good substrate. Plain sand and gravel is ok but a specialist soil or nutrient-rich substrate topped with fine gravel is much better. Root capsules can help plants with large root structures.
  4. Use CO2 injection if possible. This will drastically improve your chances of success with any aquarium plant.
  5. Use a good quality liquid fertiliser - ideally daily in combination with large frequent water changes.
  6. If you are buying fresh plants then they may need some time to adapt to their submerged form before growing properly. Be patient.

2) Why do some plants grow whilst others do not?

Different plant species have different requirements. Some are easy, some are difficult. Do your research and find out which you have and go from there. If you want to grow demanding plants you will need more light, more fertilisers, CO2 injection and more circulation. Start off with the easiest plant if you are a beginner with a basic setup. Also consider the plants’ position in the aquarium. Are the plants shaded by other plants? Are they receiving sufficient water circulation? Plants do best with good levels of circulation, especially plants that are nearer the substrate where circulation and lighting levels are usually restricted. Did you buy a healthy plant to begin with? Many plants are kept in less than ideal conditions in some shops, leaving them open to algae and nutrient deficiencies. By the time they reach your aquarium they are really struggling and if you have a new setup then the chances of success are even more limited. Only buy healthy plants. Inspect them for yellowing or pale leaves and ensure they have white roots, ideally protruding through the pots.


3) How can I fix my algae problems?

Algae is the number one reason people give up on the aquarium hobby. In a planted aquarium it can be particularly risky because we are often dealing with higher levels of lighting and nutrients - the two key components to feeding algae. The key is preventing algae from happening in the first place. This is best achieved by having lots of healthy plant growth in a well-maintained densely planted aquarium. If your aquarium does not have a large quantity of plants then unfortunately algae will be a fact of life. You will always need to address the cause of the algae rather than just fixing the symptom. By only fixing the symptom the algae will always return.

Treating algae can be done a number of ways. The following steps are helpful for most types.

  1. Manually remove as much algae as possible. Remove affected leaves and in a healthy system the plant will grow a new leaf back, which will be algae free if you fix the cause of the algae.
  2. Remove any hardscape with severe algae growth and clean thoroughly with a stiff brush and hot water.
  3. Blackouts can work for some algae. 72hrs with no aquarium lights or ambient light (use newspaper to cover the glass) can severely disrupt many types of algae without too much stress for the plants.
  4. Avoid algaecides. Most will harm your plants, or even worse, your fish.
  5. Try floating plants. These can block light, which can prove helpful, whilst growing very quickly and helping to remove excess nutrients.

We will cover algae in more detail in a future article.

4) Why do my fish keep dying?

The biggest cause of premature fish death is poor water quality. In new setups this is usually high levels of ammonia and/or nitrite due to an immature biological filter. Stocking too many fish too soon will usually result in this “new tank syndrome”. Other considerations are too much CO2. CO2 is toxic for livestock and it should me monitored to ensure levels don’t go above 30ppm (mg/l). Some fish are also incompatible, which can lead to bullying, stress in the bullied fish, and ultimately death.

Stock fish gradually. In a healthy planted aquarium the plants will usually deal with ammonia, which will help prevent water quality issues. If you use CO2 then use a CO2 drop checker that monitors CO2 levels 24/7 by changing colour depending the CO2 level.

Do your research and only stock fish that are compatible. In aquascaping larger shoals of small fish are preferable to a smaller quantity of larger fish. Tetras, rasboras and danios are excellent choices that are peaceful and provide plenty of movement and colour.

5) What’s the scum on the aquarium water surface?

Surface scum is very common in heavily planted aquariums. It’s usually caused by organics from the aquarium collecting on the surface tension. This can lead to an unsightly oily film that can in turn prevent oxygen exchange. Floating plants can help, as well as plants that are allowed to grow out from the surface (called emergent growth). A very popular device is the Eheim surface skimmer, which works as a filter with a floating portion that literally sucks in the surface water keeping it clear. Be aware though that these can accidentally suck in small shrimp and even fish so some modification may be required.

6) Why do my Amano shrimp keep escaping?

Unfortunately Amano shrimp have a habit of escaping from open top aquariums. In nature they are excellent climbers and have to do so for breeding purposes, as they transfer from one water system to another, sometime having to crawl over exposed rocks. You can limit this behaviour by having a hood or lid on your aquarium. Poor water quality and/or high CO2 can also encourage them to climb out so ensure these issues are addressed.

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(Image credit: George Farmer for Practical Fishkeeping Magazine)

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