Pruning plants in the Walstad planted tank
...time for a prune!
The combination of excess nutrients being leeched from the soil, the decomposition of organic matter in the tank and plants having not established themselves will usually translate into a Nitrate spike early on in the tank’s life. I was reading 20 Nitrates by day 12 despite vigorous plant growth and from memory it peaked about 2 weeks later at 30 or so, after which it slowly began to drop till I was reading less then 10 a month after setting up the tank.
In these early stages it is important to prune your plants to encourage new growth to continue to soak up excess nutrients. If you don’t prune, plants can hit roadblocks space wise and with excess nutrients in the water this is when algae can take over and bloom.
When pruning your plants in the early stages it is important to be ruthless. Think of plant pruning as taking a number 1 clipper to someone’s dreadlocks.
The photo on the right illustrates just how much plant matter I removed earlier this month. To give you an idea on just how much you can prune, the glass on the right is 2 foot long by 3/4 foot wide. As you can see I had no reservations about just how much plant matter I wanted out of the tank.
Don’t worry if your tank looks a little bare afterwards, that’s kind of the idea. Over time your plants will grow back and before long it will be time to prune again.
Here’s what my tank looked like after the pruning session, for comparison the photo at the beggining of this entry shows what it looked like pre-pruning.
For stem plants I recommend pruning them so that there’s still plenty of leaves left on the original stem. If you wish to propagate the plant you can replant the trimmed stems as I have done with some of my Ludwigia plants in the left background.
Plants with singular leaves, such as the Corkscrew Vallisneria (rear right) can be trimmed about an inch or more below the water level. They look best I find when trimmed at a diagonal as you still get somewhat of a natural look.
Bushy plants like the green Wisteria (centre/right rear) can be trimmed slowly bit by bit from the outer areas until you are happy with how it looks. I tend to trim mine so that it looks like treetops.
I wouldn’t bother trimming foreground plants unless you are trying to propagate them.You shouldn’t really have any tall growing plants in the foreground unless you are aiming for a specific aquascape design.
Over time as the excess nutrient level is balanced and your plants adjust to the output of nutrients your tank produces you will find vigorous plant growth will ease and pruning times will become less frequent. I had to prune every few weeks initially but now I am probably looking at 2 months or so between prunings.
Pruning isn’t the most fun job in the world but it is nice to have that ‘clean’ tank feeling again and it does have the tank environment benefit of deterring algae. I spend a good 20-30 minutes pruning usually and can only imagine how much time those enthusiasts with co2 powered aquascaped tanks must spend grooming their tanks.
Anyway try to enjoy it and afterwards make sure you sit back and take some time to visually appreciate your efforts! Your fish will also thank you for the extra bit of swimming space.
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