# Pothos as an alternative to floating plants



## HomeroThompson (Mar 15, 2020)

I was wondering if anyone had any experience having pothos instead of the usual floaters (frogbit, duckweed, salvinia, water lettuce, etc). Floaters tend to explode in numbers and hence block the light from reaching other plants. This wouldn't be a problem with pothos, while still retaining the aerial advantage (I've also read that pothos removes excess nitrogen compounds, but I'm not sure how rigorously this was tested).

Thoughts?


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## johnwesley0 (Feb 23, 2021)

I have a batch of umbrella papyrus palms in my bowl and I believe it is the same principle involved: using the aquarium water to grow the plants hydroponically. So, yes. They are definitely receiving some kind of nutrient from the water. As soon as I start up my second tank I am going to try an experiment and remove all the floaters from my bowl to see how badly the parameters suffer as a result. My hypothesis is that the emergent plants will take up the slack. But, we'll see. I agree with you that constantly removing excess floaters can be a bore.


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## rafael.nicolaidis (Dec 23, 2021)

I have a 54 l tank filtered by various types of Pothos, Philodendron and other terrestrial plants in expanded clay media. The pump is 'on' for approximately 8 h/day. Nitrates are always 0 or very low (0.25 mg/l).


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## spaquarista (Jun 23, 2021)

I have Pothos in three of my tanks (two of them also have duckweed). I don`t know scientifically how they compare but I think they would be equivalent since they are emergent plants by definition. 

The one aquarium which doesn't have floating plants, has both pothos and arrowhead.


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## dwalstad (Apr 14, 2006)

rafael.nicolaidis said:


> I have a 54 l tank filtered by various types of Pothos, Philodendron and other terrestrial plants in expanded clay media. The pump is 'on' for approximately 8 h/day. Nitrates are always 0 or very low (0.25 mg/l).
> 
> View attachment 74466


Wow! Love your setup. Houseplants used like this are fantastic for purifying water, controlling algae, etc.


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## rafael.nicolaidis (Dec 23, 2021)

dwalstad said:


> Wow! Love your setup. Houseplants used like this are fantastic for purifying water, controlling algae, etc.


They do keep the water very lean on nutrients, indeed, and I have never had an algae bloom on that tank.

However, the terrestrial plants have suffered from what I believe was lack of Ca. They had some deformed new leaves and an infestation of _Selenaspidum_. After some weeks manually removing the insects, pruning and applying neem oil, while hardening the water with some aragonite, the issue seems to be solved.


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## jatcar95 (Oct 30, 2019)

I was starting to get concerning nitrate levels in my tank a while back, so I added a pothos cutting (in addition to the floating plants). The pothos really took off the first couple weeks after being introduced! Now it has slowed down considerably and is hardly growing, but my nitrates are down. My conclusion: yes, the pothos definitely helped lower the nitrates, although it seems my tank doesn't generate enough to feed the floaters + the pothos.


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## dwalstad (Apr 14, 2006)

The leaves look chlorotic. I would try adding chelated iron. If you buy the inexpensive powdered form of chelated iron, you will have a life-time supply. 
Iron is the one nutrient that water alone may not supply enough of (my book, pp 167-170). 
I add a solution made from FeEDTA powder when my floating plants start to disintegrate.


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## YodelMogul (Oct 7, 2021)

rafael.nicolaidis said:


> I have a 54 l tank filtered by various types of Pothos, Philodendron and other terrestrial plants in expanded clay media. The pump is 'on' for approximately 8 h/day. Nitrates are always 0 or very low (0.25 mg/l).
> 
> View attachment 74466


 Do you have any more info about this setup (pump, plant pot, drain, etc)? This is what ive been looking to do.


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## rafael.nicolaidis (Dec 23, 2021)

The pump is from a brazilian manufacturer, link here: Motobomba SB2700 - Grupo Sarlo
Flow rate is 2740 l/h and height of water column is 2,45 m. I have attached a sponge prefilter to it.

Make sure that the *height of water column* of the pump you choose is adequate for your design.

These are the pots:
Jardim Vertical Mamute - Kit 5 Vasos - Ecotelhado
I have filled them with hydroton pellets (expanded clay), except for the last one, in which I have perlon sheets and no plants.
Plants are mostly _Pothos _variants, but we have _Philodendron_, mini _Anthurium _and _Oxalis. _


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## johnwesley0 (Feb 23, 2021)

My pothos hack (an old HOB casing now hanging _inside _the tank.)








The literature says start with a cutting, but I didn't know that until _after _I completely disemboweled a small pot purchased at the corner grocery. I should probably start a cutting just in case this specimen goes south.


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## YodelMogul (Oct 7, 2021)

johnwesley0 said:


> My pothos hack (an old HOB casing now hanging _inside _the tank.)
> View attachment 74535
> 
> The literature says start with a cutting, but I didn't know that until _after _I completely disemboweled a small pot purchased at the corner grocery. I should probably start a cutting just in case this specimen goes south.


 Just curious why even bother with the hob casing? 

On a side note i hung mine right in the tank and it started to put down structural roots on the tank frame. Kinda neat.


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## johnwesley0 (Feb 23, 2021)

YodelMogul said:


> Just curious why even bother with the hob casing?
> 
> On a side note i hung mine right in the tank and it started to put down structural roots on the tank frame. Kinda neat.
> View attachment 74536


Didn't want it to sink to the bottom of the tank?


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## SamOfChaos (10 mo ago)

Very interesting. I actually just cultivate my pothos in an hob with crushed lava rocks.


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## johnwesley0 (Feb 23, 2021)

Yes. This is my HOB setup six weeks later:








I really like the way it puts down additional roots as it progresses across the top of the tank.


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## MudLily (9 mo ago)

If you get one of the spiffy Fluval tanks with the false walls built-in, they make great spaces for pothos. The old Spec models with the minimalist light and the cheap clear plastic "lid" were fantastc, and you could even put a goose-neck clip-on light to target the pothos.

Pothos and other pure terrestrial plants are terrific. I suspect they have higher nutrient demands not only due to the aerial advantage, but also because their growth has to be more dense in order to support their weight against gravity.

The lack of commercial innovation in this direction is honestly disappointing.


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## Steven F (Aug 1, 2021)

MudLily said:


> Pothos and other pure terrestrial plants are terrific. I suspect they have higher nutrient demands not only due to the aerial advantage, but also because their growth has to be more dense in order to support their weight against gravity.


My observations of plants indicates it is the size of the plant that matters. Bigger plants need more nutrients to grow. Duckweed and very small plant doesn't need much to grow very fast. So while all my other plants didn't have enough nutrients to grow Duckweed did very well. For each gram of growth you need a fixed amount of nutrients. So duckweed a very small plant doesn't need much and then it splits into two plants instead of growing bigger. Pothos and Anubias Nana (a common plant used submerged in aquariums which can also grow out of the water are closely related. And their larger size will require more nutrients to grow and it rarely reproduces so it just gets bigger.

Once reason why algae is hard to control is that it is by far the smallest. So it can grow in excessively low nutrient levels that even Duckweed can't grow. I have seen Algae srvive in water with aTDS of 1ppm (close to pure water. I can't get any regular plant to grow at that level. 



dwalstad said:


> The leaves look chlorotic. I would try adding chelated iron. If you buy the inexpensive powdered form of chelated iron, you will have a life-time supply.
> Iron is the one nutrient that water alone may not supply enough of (my book, pp 167-170).
> I add a solution made from FeEDTA powder when my floating plants start to disintegrate.


Fe EDTA is only usable if the water PH is no higher than 6.5. If the PH is higher than that the iron rusts and is no long available to plants. Fe DTPA is a better choice since it is stable up to PH of 7.5 to 8.


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## MudLily (9 mo ago)

Size + growth speed. Anubias is often recommended to beginners because with its very slow growth rate, it can often be kept with minimal considerations in regards to nutrients despite its density/size. Even java fern is pretty sizeable and often does fine without special considerations.


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## johnwesley0 (Feb 23, 2021)

MudLily said:


> Size + growth speed. Anubias is often recommended to beginners because with its very slow growth rate, it can often be kept with minimal considerations in regards to nutrients despite its density/size. Even java fern is pretty sizeable and often does fine without special considerations.


I would even go one step further. It's size + growth speed + reproductive rate. Individual Frogbit and salvinia plants may have a minor effect individually on nitrates in the water column. But, I have found especially after they have "carpeted" the surface the nitrate level rises but plummets right after I have removed about half the floaters and they resume filling up the surface area. IMHO, "fast growth" includes the ability to reproduce quickly.

And, not to put too fine a point on it, my _anubias barteri_ are among the slowest growing organisms I have ever owned.


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## dwalstad (Apr 14, 2006)

MudLily said:


> Size + growth speed. Anubias is often recommended to beginners because with its very slow growth rate, it can often be kept with minimal considerations in regards to nutrients despite its density/size. Even java fern is pretty sizeable and often does fine without special considerations.


Anubias and ferns generally don't grow fast enough to compete with algae. (I've seen pure Anubias tanks completely overrun with beard algae.) To address this problem, you can combine slow-growers with emergent plants (floating plants, houseplants, etc) in the same tank. However, I would never use a soil layer or deep gravel in this kind of setup. You need fast-growing rooted plants to keep the substrate from going anaerobic and toxic.


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## MudLily (9 mo ago)

dwalstad said:


> Anubias and ferns generally don't grow fast enough to compete with algae. (I've seen pure Anubias tanks completely overrun with beard algae.) To address this problem, you can combine slow-growers with emergent plants (floating plants, houseplants, etc) in the same tank. However, I would never use a soil layer or deep gravel in this kind of setup. You need fast-growing rooted plants to keep the substrate from going anaerobic and toxic.


Great point, Anubias seems to be a bit of an algae magnet.

I actually forgot this was under the El Natural board when I replied!

So when I said "beginner" I was referring more to the average person who walks into a fish store knowing nothing, wants the cheapest/easiest way to keep some fish alive, and has never considered plants as an option. Ironically, their cheap lighting, cautiously recommended conservative tank stocking, and reluctance to spend money on special substrate or fertilizer actually does a reasonable job of controlling algae, while a little bit of slow plant growth goes a long way to increase their enjoyment of the tank and gives them confidence to explore a little more into the plant side.


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## dwalstad (Apr 14, 2006)

Well-put!


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