So you started a planted tank. You started with a decent substrate. You placed some rocks and some driftwood and you began planting some upright plants for height, some medium sized plants for middle ground and a species or two of carpeting plants. You probably have some nice and powerful lights and a fertilizing schedule. Ok, I know, your aquarium probably still looks a little barren, aside from those few sprigs of plants you so carefully placed in strategic spots, allowing for growth. Fast forward 3 weeks and … Oh dear! You probably have a mess of algae that has covered your rocks, your plants, the driftwood and even your substrate, suffocating the remaining plants into total submission.
Well, you created a perfect environment for algae! When you set up a tank, it’s critical for your aquatic plants to establish a dominance, soaking up all the nutrients they can. If you don’t have enough plants, algae moves in and believe me, it will smother everything, thriving on the excess nutrients your plants aren’t using.
So how can you avoid this when you set up your first aquascape?
It is so easy, it is almost laughable!
The key is fast growing stem or floating plants. Add as much of these as you can, without totally shading out the plants below. They are excellent at soaking up excess nutrients and some even release chemicals (called allelochemicals) that retard the growth of algae. The magic is that they don’t disrupt your perfectly planned layout. Simply float them in your aquarium for the first few weeks, or until the feature and carpeting plants have had a chance to take hold and spread. Also, hold back a bit on fertilizing until your plants really start growing, and then only fertilize in proportion to the amount of plants you have in the aquarium. Gradually up the fertilizing, keeping track of algae and reducing fertilisation it if you see algae starting to crop up. This helps swing the balance in favour of your chosen aquatic plants, and algae won’t have as much of a chance to gain a foothold.
Some plants that work particularly well at keeping algae at bay in the early weeks of a newly set up aquarium are Hornwort, any hygrophila species, or any floating plant. But be careful — some can quickly become a pain to get rid of since they grow so quickly and tend to hide in everything — and yes I am looking directly at you, Mr. Duckweed!
If algae gets out of balance, the best thing to do is to reduce your lighting period, put back the floating plants, reduce your fertilizer dosing if you are dosing too much, make sure your water is steady. Then wait until you have restored balance again. As long as everything is balanced, your plants should be able to out-compete the algae and your aquascape will be nicely back on track.
To keep algae out, the latest research shows that a timer on you lights may be one of your best investments. Set your timer so that your lights switch off for one hour over the mid-day. Fish and plants have no problems with this, as it somewhat mimics overcast skies during tropical storms, which in nature is a common occurrence. Algae, however, seem to hate this and over time will completely disappear.
Of course, CO² in planted aquaria almost guarantees that you will have no, or very little algae problems. So how about building your own?