How to keep floating plants in aquarium

Floating plants are a great addition to the home aquarium. The first few times we tried to keep floating plants, it all failed. Water lettuce, frogbit, and red root floater all melted away and died within days.

After multiple tries, we think that we have figured out the tricks to keep floating plants in the aquarium! The YouTube video below summarizes 8 essential tips for keeping floating plants alive and thriving in the home aquarium.

For beginners we recommend Salvinia, or water spangles, as the first starting floating plant. It is also easy to remove, as a great contrast to duckweed.

NA2 Live Water Spangles, Salvinia Minima, Water Velvet, Free Feeding Ring Aquatic Plant Aquarium Fish Tank, Top Water Plant, Floating Pond Plant, Pond, Goldfish, koi (24+ Spangles)

There are many advantages of Salvinia, including it being one of the easiest floating plants to keep alive.

Salvinia leaves with water droplet (Artistic Photography)

Some photos of spherical water droplets on Salvinia floating plant.

I think Salvinia is one of the easiest floating plant to keep in an aquarium. It has 3 forms Primary form, Secondary form, and Tertiary form and will adopt the most suitable form for whatever conditions is in your aquarium. (The photos shown below are Primary form. Initially, when I bought it, it was in Tertiary form.)

Monte Carlo Low Tech (No CO2 Carpet Plant)

Monte Carlo plant from Argentina is often said to be the easiest carpeting plant and does not require CO2.

We try it in our low tech tank beside our Ludwigia Sp. Red (2 months old and still alive).

We also cover Monte Carlo plant care tips, guide, and how to plant Monte Carlo.

Basic care tips:

– Moderate or high light recommended
– Nutritious substrate needed
– Fertilization recommended (For example Tropica Fertilizer)
– Trimming required (ideal thickness of Monte Carlo carpet is 1 to 1.5 inches)

Micranthemum Monte Carlo New Large Pearl Grass Live Aquatic Plant in Tissue Culture Cup for Aquarium Freshwater Fish Tank by Greenpro

The above video is Day 1 (21 July 2020) of planting Monte Carlo. Hopefully it will survive and carpet in the low tech tank, without CO2!

Monte Carlo (Day 2) in low tech tank. I pushed some of the Monte Carlo plants deeper into the soil using tweezers. The bright green color of MC (Monte Carlo) is really striking.

Monte Carlo Carpet Without CO2 (Day 7 Update)

Day 7: Noticeable improvement in the Monte Carlo carpet in my low tech, no CO2 tank! I do have a mini “time lapse” photo of the Monte Carlo before and after, the difference is quite noticeable. The Monte Carlo has “rooted” itself deeper into the substrate. Hopefully it continues to improve and spread out even more.

Monte Carlo Low Tech No CO2 (Day 7 Update). Compared with Day 1 or 2, it has rooted itself deeper into the substrate!

Day 13: Monte carlo time lapse (Day 13 Photo Time Lapse), Turning a little brown!

Monte Carlo low tech time lapse (photo montage), up till day 13. Growth is noticeable, but yet there is some yellowing and browning. I think the Monte Carlo is still adapting, and possibly transitioning from emersed to submersed. I just heard that another plant, Marsilea hirsuta, may be even easier than Monte Carlo to grow. Tropica rates the Marsilea hirsuta as easy, while Monte Carlo is rated medium. Maybe will try it if the Monte Carlo melts and dies.

Monte Carlo low tech no CO2 Day 13 update. Some browning and yellowing is observed!

Monte Carlo Low Tech Day 25: Growing Upwards!

This is Day 25 of growing Monte Carlo in low tech, no CO2 tank. The Monte Carlo is growing and surviving, however the growth is vertically upwards instead of carpeting horizontally. In other words, the Monte Carlo plant is not carpeting.

How do we ensure that the Monte Carlo carpets and grow horizontally? Please comment below if you have any suggestions!

Monte Carlo growing upwards instead of carpeting.

Easy Floating Plant: Salvinia

This plant Salvinia (to be precise Salvinia Molesta or Giant Salvinia) is a super easy floating plant. It has 3 forms: Primary, Secondary, Tertiary Forms. I started with Tertiary Form Salvinia, and now have a lot of Primary Form Salvinia, as well as a few Secondary Form Salvinia.

I find that Salvinia is an easy floating plant because:

1) It only requires medium light

2) It has 3 forms and will evolve to the form that is most suited for your tank. The Tertiary Form is usually for outdoor ponds.

3) It is ok with getting a bit wet. Many other floating plants must be completely dry or else they may rot.

4) It has short roots. Hence, there is no need to trim its roots.

5) Easy to remove if you don’t want it. Most of its leaves are linked together. Hence you can remove all the leaves in a few grabs. This is in contrast to duckweed, which is notorious for being hard to remove.

I find that the Primary Form of Giant Salvinia is quite similar to Salvinia Minima, and the Secondary Form of Giant Salvinia is quite similar to Salvinia Natans! Could they be the same species?

Tropica also sells this version of Salvinia which they call it Salvinia auriculata.

24 Water Spangles (Salvinia Minima), Live Aquarium/Aquatic/Floating/Pond/Beginner Plant by G&Z

Amount of Potassium in Singapore Water

The official document for Drinking Water Quality analysis can be found on the PUB website.

Note that the above document does not contain any information on potassium (K).

Potassium Content in Singapore tap water

I managed to find another source (dated 2002) on potassium content in NEWater: In page 16, the potassium levels are stated as:

Range (Potassium): 0.504 to 3.07 mg/L

Mean (Potassium): 1.08 mg/L

Sodium Content in Singapore water

Range (Sodium): 3.16 to 42.1 mg/L

Mean (Sodium): 13.35 mg/L

Potassium in Planted Tanks

For aquarium plants, “potassium content should be at least equal to sodium content or higher.” (

Usually, the solution is to dose potassium fertilizers (for example potassium sulphate).

Seachem Flourish Potassium 500ml

In addition, many sources recommend a level of around 20 ppm of Potassium for planted tanks (see for instance this site). That is 20 times the amount found in tap water! Other sources push it further, there are sites that recommend up to 50 ppm of potassium.

AR Mini Low Tech Day 50

Read more at: Alternanthera Reineckii Mini Low Tech

Day 50 (12 March 2020): The aquarium light was upgraded around 10 days ago on 2 March 2020. It has helped the AR Mini in my opinion, making it slightly redder. The AR Mini is very much alive in the low tech tank! I think this dispels the myth that Alternanthera Reineckii Mini requires CO2 to live.

Anubias Rhizome tied too tight

Anubias tied too tightly

I think one of my Anubias rhizomes died (rotted) due to it being tied too tightly. The Anubias rhizome is supposed to be hard and green, if it is soft or brown, something is wrong.

For Anubias, the rhizome is the most important part of the plant, if it is dead, the whole plant will die.

Another reason for the Anubias rhizome rotting is the dreaded Anubias disease, but I don’t think it is the case here because another rhizome just next to the rotted rhizome is perfectly healthy.

Hence, the conclusion is that the Anubias rhizome most likely died from being tied too tightly by the string. It was at the back of my tank so I didn’t really notice it at first. I only noticed it when I saw a new leaf sprout out from the rotting rhizome, but the new leaf melted soon after. Usually, when new leaves melt, it is a sign of something wrong. Upon taking the entire Anubias plant out, I then realized that the rhizome had turned mushy.

The original Anubias was tied (by the seller) with thick string. I don’t really blame them for tying too tight because it is not easy at all to tie Anubias (too loose and it will not stay in place). I cut off the old string, threw away the rotted rhizome, and re-tied the healthy Anubias lightly with sewing thread.

Probably the same problem can occur for Java Fern, Bucephalandra, the rhizome may rot if tied too tightly.

Alternanthera Reineckii Mini Low Tech

AR Mini Low Tech

This blog post is an experiment on whether Alternanthera Reineckii Mini (AR Mini) can survive in a low tech (i.e. no CO2 supplementation) tank.

The plant used is Tropica tissue culture as shown below:

Tropica Alternanthera reineckii ‘Mini’ Live Aquarium Plant – in Vitro Tissue Culture 1-2-Grow!

Traditionally, Alternanthera reineckii ‘Mini’ (AR Mini) is grown in high tech, high light tanks where it will grow into a deep red purplish color. In low tech, lower light tanks, I am trying to see if it can still grow, albeit less red. Maybe a lighter red or olive / bronze color like its cousin Alternanthera Roseafolia (below), would be a good enough result.

Mainam Alternanthera Reineckii VAR. Roseafolia Telanthera Freshwater Red Stem Live Aquarium Plant

Tank Parameters and Fertilization

Tank size: 5 Gallon (I am using this tank: Ripples Premium Aquarium Glass Fish Tank (with Filter and LED Lights) 18.9L)

Light: It is just a basic starter kit LED light with 7 bulbs. Apparently rated just 2.9W.

Substrate: Aqua Gro Aquarium Soil by Ocean Free (it is a local brand by Qian Hu). It should be something similar to ADA Aqua Soil Amazonia II Normal Type (9L), maybe with less nutrients.

Fertilizer: So far I am only using Tropica Plant Growth Premium Fertiliser – 125 ml, one pump per week after water change.

Lighting schedule: I am using an electronic timer with 12 hour photoperiod: 10am-4pm, 5pm-11pm. In between 4-5pm is a siesta (rest/blackout) period (to build up some CO2 if possible).


Day 1 (23 Jan 2020): This is the first day of planting. Still quite purplish undertones. To plant the Tropica tissue culture, I plucked off some of the leaves on the lower stem, and then inserted it into the substrate. No trimming of roots were done (the roots were not long anyway).

Day 3: The next video below is the 3rd day. The pinkish red colors on the underside are mostly gone (quite worrying), but the plants is clearly alive and it has oriented its leaves to face upwards! It is now a olive color with hints of red/pink.

Day 4: Video below. Not much different from Day 3. I realized that there is a Dwarf Sag small plantlet with runner amongst the AR Mini. The Dwarf Sag is one plant that is thriving in the tank. It started with 2 mother plants and now there are at least 8 plants propagated naturally via runners. If necessary, I may remove the dwarf sag (just the one amongst the AR Mini).

Day 5: Melting and shedding of leaves. This is day 5 of planting the AR Mini in the low tech tank. A total of 3 leaves were shed today. I think it is either (a) transitioning from emersed to submersed growth or (b) dying. Hopefully it is the former!

Day 6: Just one leaf melt today. One entire stem got uprooted, maybe it was the snail or the shrimp that disturbed it. There is a little frenzy among the neon tetras and Amano shrimp trying to grab the shrimp pellet. I removed a dwarf sag plantlet among the AR Mini, and replanted the uprooted stem there.

Day 7: No shedding of leaves today, which is good news. I spotted something that looks like hair algae, it could well be a disintegrated Marimo moss ball from “Secret Shrimp Society”. Water change was done, as well as dosing of Tropica Premium Nutrition liquid fertilizer. I ended up trimming the Cryptocoryne Wendtii as its leaves were almost reaching the water surface. I also removed the disintegrated Marimo moss balls from “Secret Shrimp Society” as it was starting to look like hair algae.

Day 10: This is day 10 of growing Alternanthera Reineckii Mini in a low tech tank. The leaves seem to have “perked up” and are slightly pinkish. Overall it looks better than on day 7, I think. The contrast between day 3 is also quite clear. No CO2 in this tank.

Day 13: The AR Mini has changed to a nice orangey-red. There has been shedding of around one leaf per day. The plant still looks alive overall, and in fact has grown taller than the Dwarf Sag beside it. There has been some trimming of the taller plants in the tank (crypts and Anubias).

Day 16: It has passed the 2 week mark. The AR Mini is still alive in the low tech tank. I do observe some new leaves growing.

Day 20: The AR Mini plants are getting more bronze color and less red. The undersides are still a little pinkish red though. Overall quite surprised at the result in my low tech tank. (I was half expecting the plants to die.)

Day 50 (12 March 2020): The aquarium light was upgraded around 10 days ago on 2 March 2020. It has helped the AR Mini in my opinion, making it slightly redder. The AR Mini is very much alive in the low tech tank! I think this dispels the myth that Alternanthera Reineckii Mini requires CO2 to live.

Day 50: AR Mini is still doing well in low tech tank.

Further Ideas

I may add some root tabs in the future (will clearly indicate the moment when I do add it). According to the below video review (it is really excellent), the best root tab on the market seems to be Seachem Flourish Tabs Growth Supplement – Aquatic Plant Stimulant 40 ct.

Update (31 March 2020): I have added 2 root tabs (Seachem Flourish). One right next to the AR Mini, and another a few inches away.