Planted aquariums can be a beautiful addition to your home, but the plants require regular maintenance to keep them looking their best.
The thing about aquatic plants is that you can’t prune them continuously and expect new shoots. Aquatic plant species are always in the process of shedding old growth to put energy into new shoots and leaves. If you trim the top of your stem plants to keep them short, eventually those old stems might not provide any new growth as they will be too far-gone to do much of anything.
What you should be doing every time you trim tall stems is completely discard the lower portion, and replant the healthy top you’ve just trimmed off. Because it is healthy and adapted to your tank conditions already, it will quickly sprout new roots and begin growing.
With that said, there are some species such as Rotala Rotundifolia that tolerate trimming and will still put out new shoots from older stems even after a few trims. However, the bottom stems will still deteriorate eventually and will need to be discarded. It’s easier to trim and replant tops than keep track of which old stems need to go next.
It makes sense to discard old stem sections that have been shaded by the growth above. They won’t look as nice as the freshly trimmed tops and won’t bounce back as well.
By providing plants with an enriched substrate or root tabs and regular water column fertilisation, plants will grow healthy for longer, and bounce back faster from the mechanical stress of being trimmed.
When you’re pumping CO2 and fertilising heavily, trimming and replanting of stem tops will be a regular requirement. Low-tech tanks will require much less frequent trimming.
It’s important to remember that most aquatic plants do not renew old or damaged leaves. They will always put their energy into new growth, absorbing old and damaged leaves to do so.
Fast growing plants and stem species in particular will happily discard old growth that is underperforming, whether it’s shaded, deteriorating, or otherwise damaged. This is because they are generally able to quickly create new growth that will provide better energy conversion.
With regular fertilisation, the breakdown of older leaves will be slowed, and the overall appearance of leaves will be improved as they receive the nutrients they need for healthy growth.
Older leaves on slow growing plants such as anubias may even revitalise if nutrition is improved, as these slow growers need their leaves to perform for longer periods of time.
Damaged or deteriorating plant growth in general should be discarded to reduce the chance of algae appearing, as it loves the nutrients leaking from these leaves.
You’ve put in some plants, and after a while they have finally settled in to your tank and are starting to grow. It’s comforting to see and a great indication you are on the right track. Now, rather than leaving the plant alone, the best thing you can do for it is to trim off the healthy top section, discard the old lower stem (with roots) and replant the top. Those old sections of the plant that were grown in different conditions won’t improve and will only hinder the plant. Not only that, the new section of growth is going to look a lot nicer and will be completely adapted to the conditions in your tank.
From The LCA Team
Every Solution For Your Aquarium
Brown Algae (Diatoms)
Diatoms most commonly appear as small soft clumps of brown or yellowish green particles, in patches or as a stringy brown mass. It is extremely common in new aquariums that are still cycling but can also appear in tanks using a DIY dirted substrate or those with low plant mass.
It can also appear if your filter is unable to provide a sufficient amount of filtration and beneficial bacteria for your bio-load.
Most of the time with diatoms, it’s simply a case of waiting for your aquarium to mature. You can siphon or otherwise manually remove visible diatoms but they will quickly reappear. Once your cycle has established, diatoms will rapidly dwindle. For faster results, you can use commercially available products to help speed up the cycling process.
If you’re using a DIY dirted substrate, it might be leeching ammonia into your water column, which can also cause diatoms to appear. Check that you have a sufficient “cap” over the dirted portion of your substrate and increase its depth if not. Try not to disturb your substrate while planting as this will also release ammonia.
As always, increasing the amount of plants in your aquarium or encouraging healthy plant growth is always beneficial, both in reducing algae and for the overall health of your aquarium system.
There are plenty of livestock options that will eat diatoms – snails, shrimp, otocinclus and more. Apart from previous suggestions, if your tank is cycled and can support them, consider adding a crew of algae eaters!
Not enough nutrients for plant mass
One of the biggest mistakes you can make in a planted tank is to reduce fertilisation in an attempt to get rid of algae. In fact, this will lead to more algae, as the plants stop growing from a lack of all the necessary nutrients – allowing the algae to use what’s there instead. You can’t starve algae without starving plants!
Plants need more nutrients than algae to grow lush and healthy. Algae can thrive from a very small amount of nutrients, whereas plants really need a balanced mix of both macro and micro nutrients to survive.
Achieving the right balance can be difficult. Regular dosing with a comprehensive fertiliser is essential. You need to consider the volume of water in your aquarium, plant mass and just how “hungry” your plants are.
For example, in a low-tech system using medium to low lighting and no pressurised CO2, plant demands will not be very high. Fertilisation will still be required but at a reduced rate. Fertilisers such as LCA Low Tech Complete and LCA NP Free are ideal for these systems as they supply a smaller amount of nutrients.
In a tank using intense lighting and pressurised CO2, your plants will want to grow more vigorously and will rapidly use up the nutrients you supply. Estimative Index (EI) dosing with fertilisers such as LCA All In One Premium is an excellent way to ensure you’re delivering enough nutrients – in fact, dosing with the EI method ensures an excess of nutrients are supplied, so you can then focus on lighting and CO2 if there are any issues.
You can also add root tabs to your substrate to enrich it or to target specific nutrient-hungry plants.
To reiterate – you need to find the right balance of nutrients for your tank – not too much, not too little.
It’s no surprise that algae will show up in a tank with inadequate filtration. As we’ve discussed, the bacteria in your filter converts the ammonia that algae loves into other compounds. If your filter can’t remove the solid waste and hold enough bacteria for the livestock and size of your aquarium, your water is always going to be low quality with excess ammonia and other organics present.
While many types of filters exist, not all are created equal. You want a filter that can:
There is no such thing as “too much” filtration. The more water your filter can circulate per hour, the better – as long as your livestock don’t mind the flow!