Hey everyone,
I'm just starting out with plants and thought I'd begin with floating plants - they seem like a great way to get started. I've got two tanks, one's 29 gallons with a bunch of fish (6 neptunes, 2 mollies, 2 neon tetras, and a small angelfish) and the other's 10 gallons (2 mollies, 3 swordtails, and a guppy). I picked up some duckweed a few weeks ago and initially put it in the bigger tank while it was still cycling. Later on, I transferred some to the smaller tank.
Fast forward a few weeks, and I've noticed the duckweed in the bigger tank has turned red and isn't growing much - which is weird for duckweed. On the other hand, the duckweed in the 10-gallon tank has taken off (it's about 4 times what it was when I first put it in). I've added some pictures below.
The bigger tank has a hang-on-back filter, and I think the constant water flow might be submerging the duckweed. I printed some feeding rings and added them over a week ago, but I haven't seen much improvement yet. Both tanks have lids, so I'm not sure what's going on with the bigger tank.
Why is my duckweed turning red
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Giggletons - Posts: 172
- Joined: Wed Apr 27, 2022 7:36 am
Re: Why is my duckweed turning red
I think I've identified the duckweed as Gkento4t, which is actually a type of spirodela. I've come across some wild azolla that turned red when it was exposed to too much direct sunlight, so maybe try moving it to a shadier spot in the tank? It's worth noting that Gkento4t is different from the more common lemna variety of duckweed, despite the name. Also, the underside of the Gkento4t type is supposed to have a reddish hue, which might be what you're seeing.
By the way, I also noticed what looks like some Water Spangles, or salvinia, in the tank, and that one seems to be thriving.
By the way, I also noticed what looks like some Water Spangles, or salvinia, in the tank, and that one seems to be thriving.
Re: Why is my duckweed turning red
I'd like to correct the plant species identification - it seems you have two different plants floating in your tanks. One is indeed a species of Salvinia, not duckweed. Research suggests that Salvinia auriculata is often associated with aquarium plants, but some authors argue this might be inaccurate. According to Kasselmann (2003), S. molesta is likely the species most commonly found in aquaria, possibly a natural hybrid of S. auriculata and S. biloba.
The other plant, I agree, is probably Spirodela polyrhiza, commonly referred to as Gkento4t Duckweed. Note that true duckweed belongs to the genus Lemna. In your photos, you can see the differences between the two plants. Salvinia tends to grow in strings, quite distinctive.
Both plants require good light and nutrients to thrive. Are you using any fertilizer, specifically liquid fertilizer, in your tanks?
The other plant, I agree, is probably Spirodela polyrhiza, commonly referred to as Gkento4t Duckweed. Note that true duckweed belongs to the genus Lemna. In your photos, you can see the differences between the two plants. Salvinia tends to grow in strings, quite distinctive.
Both plants require good light and nutrients to thrive. Are you using any fertilizer, specifically liquid fertilizer, in your tanks?
Re: Why is my duckweed turning red
I'm not using any fertilizer, no. I've got a fair amount of algae still growing in the tank, which I thought the duckweed would help control by using up the available nutrients.
My main priority is keeping these plants healthy, so I'm not too fussed about the red color or the mix of different plants - as long as they're thriving, I'm happy.
The tank doesn't get any direct sunlight, but it does have the standard lid lights that came with the TopFin kit. The waterline is pretty high, almost touching the lights, so I can try moving the plants to a spot that's not directly under the light. I figured more light would be better, but maybe that's not the case.
What should I do to get these plants in better shape?
My main priority is keeping these plants healthy, so I'm not too fussed about the red color or the mix of different plants - as long as they're thriving, I'm happy.
The tank doesn't get any direct sunlight, but it does have the standard lid lights that came with the TopFin kit. The waterline is pretty high, almost touching the lights, so I can try moving the plants to a spot that's not directly under the light. I figured more light would be better, but maybe that's not the case.
What should I do to get these plants in better shape?
Re: Why is my duckweed turning red
There are just a couple of strands of Salvinia in your tank, and they look to be in good shape, so fingers crossed they stay that way. This is a really beautiful little plant, and the upper surface of the leaves can sometimes take on a lovely silvery green hue. As for the "duckweed", I've never kept it myself, and I'm not sure if the excessive red color is just its natural color or a sign of some underlying issue with the lighting or nutrients. I've seen Salvinia turn red like this when it's dying off, but I'm not sure if that's what's happening here.
I've found that Seachem's Flourish Comprehensive Supplement for the Planted Aquarium is a great addition to any tank with floating plants. Brightwell Aquatics' FlorinMulti is another good option. Both of these products are complete and proportional, which is really important. They might be worth trying out.
I'd also recommend adding some more substantial floating plants to your tank. Water Sprite is a great option, and Water Lettuce and Frogbit are also good choices. Some stem plants like Pennywort can also do well floating on the surface. These plants are generally easier to maintain and do a great job of absorbing ammonia and ammonium, which can help prevent problem algae from growing.
I've found that Seachem's Flourish Comprehensive Supplement for the Planted Aquarium is a great addition to any tank with floating plants. Brightwell Aquatics' FlorinMulti is another good option. Both of these products are complete and proportional, which is really important. They might be worth trying out.
I'd also recommend adding some more substantial floating plants to your tank. Water Sprite is a great option, and Water Lettuce and Frogbit are also good choices. Some stem plants like Pennywort can also do well floating on the surface. These plants are generally easier to maintain and do a great job of absorbing ammonia and ammonium, which can help prevent problem algae from growing.