Will Pothos Out Compete my plants?!

[Ariel S]

Hi-

should I be worried that Pothos will outcompete my water column plants? 

back story: 
i was growing Pothos in one of my breeding tanks, it was a 10 gallon that housed about 150 endler females, I had a huge Pothos growing from it to help keep the water clean, it’s about 10 feet long with huge leaves. (side note: it was wonderful it kept the water free of ammonia and nitrite despite the heavy bio load). I recently sold all of my endlers and broke down the tank, so I move my giant Pothos to my 40 gallon breeder (low fish stock) tank and now I’m worried that it’s going to outcomplete the plants in that tank. 

any advice is welcome! 
current plants in the tank with the Pothos: lots of Java fern, Amazon sword, tons of years old crypts, Anubias, pogostem octopus, and Java fern. I currently use easy green and root tabs. 

The tank doesn’t look great, and you can’t see the whole thing in the picture, but it’s been doing some serious bouncing back from a massive Blackbeard and other algae breakout when I left it practically unattended for almost 3 months while I was out of town. 

[jwcarlson]

In my experience it's hard for me to keep nitrates in tanks with pothos.

[Wisdom]

I'm sort of chancing the same question. I have Pathos, Philodendron and Calathea growing out of the top of my tank. I notice my ferns are turning brown and leaves are dyeing off. I'm not certain I would blame the house plants though. I suspect a potassium deficiency. 

However I would suggest you move your light. The Pathos looks like it's depriving your aquatic plants of those beautiful rays! 

[cmo1922]

On 3/8/2024 at 11:01 PM, jwcarlson said:

In my experience it's hard for me to keep nitrates in tanks with pothos.

This. Eventually I have to pull the pothos. I have one in my 20 gal I think I'm going to have to pull soon. I use them when I start up tanks to control nutrients, or if I don't plan to keep other plants in the tank. If you find you can't keep your nitrates above 5 ppm and you are fertilizing, I would recommend pulling.

On 3/8/2024 at 11:53 PM, Wisdom said:

I'm sort of chancing the same question. I have Pathos, Philodendron and Calathea growing out of the top of my tank. I notice my ferns are turning brown and leaves are dyeing off. I'm not certain I would blame the house plants though. I suspect a potassium deficiency. 

However I would suggest you move your light. The Pathos looks like it's depriving your aquatic plants of those beautiful rays! 

Also, OMG the little house, where did you find that? Not to derail from poster's question, but this is too good!

[Ariel S]

On 3/8/2024 at 10:53 PM, Wisdom said:

I'm sort of chancing the same question. I have Pathos, Philodendron and Calathea growing out of the top of my tank. I notice my ferns are turning brown and leaves are dyeing off. I'm not certain I would blame the house plants though. I suspect a potassium deficiency. 

However I would suggest you move your light. The Pathos looks like it's depriving your aquatic plants of those beautiful rays! 

Thanks! Well I’m not doing to raise my light if I’m not going to end up using the Pothos in that tank. I don’t want the other plants to die. I’m using legos hahaha

[Wisdom]

I think the Legos are a great idea! endless adjustability, but I don't think you need to raise. I was thinking you could just move the pathos leaves a bit towards the front of the tank to let some of the light through. They really don't need to be that close and it will still get plenty of light indirectly. 

[Tony s]

Pothos are great plants, but a word of caution.

when using Pothos, make sure your vines and leaves are not soaking in your aquarium water. When that happens, the same toxins that affect cats can leach into the water and be harmful to your fish. The roots themselves are fine. It’s just the stems and leaves 

[flyingcow]

On 3/9/2024 at 1:12 PM, Tony s said:

Pothos are great plants, but a word of caution.

when using Pothos, make sure your vines and leaves are not soaking in your aquarium water. When that happens, the same toxins that affect cats can leach into the water and be harmful to your fish. The roots themselves are fine. It’s just the stems and leaves 

Is there information on this being toxic to fish? Never heard of this before! Not trying to question you, but I have been having an issue with fish death that I'm 99% sure is parasitic, and a parasitic treatment has stopped the fish death for 6 weeks so far, but now I want to understand this better.

[Tony s]

On 3/11/2024 at 3:46 PM, flyingcow said:

Is there information on this being toxic to fish? Never heard of this before!

Have I had this happen, no, thankfully. But Luke from Luke’s Goldie’s lost a tank full of fancy goldfish. The only explanation for it, was he runs open top tanks, and the vines were left trailing in the water. 
 

question away. I am more than capable of being wrong. I am trying to learn, same as everyone else here. 
 

going to ask some experts though @dasaltemelosguy. Could we pick your brain on this? Can be a bit confusing for some of us trying to learn. I have heard roots are safe, but the stem and vine can leach toxins?

[MattyM]

On 3/11/2024 at 2:46 PM, flyingcow said:

Is there information on this being toxic to fish?

Right here, on the good ol' AC site:

https://www.aquariumcoop.com/blogs/aquarium/pothos#:~:text=You often see pothos used,having problems with this plant.

TL;DR - nope, pothos are fine, even the stems and leaves. Many of my new shoots are in the water for weeks before I either trim or pull them above the lid, never had any problems. 

And yes, with pothos I need to fertilize more often, and trim the roots here and there. 

Edited March 11 by MattyM

[jwcarlson]

On 3/9/2024 at 12:12 PM, Tony s said:

Pothos are great plants, but a word of caution.

when using Pothos, make sure your vines and leaves are not soaking in your aquarium water. When that happens, the same toxins that affect cats can leach into the water and be harmful to your fish. The roots themselves are fine. It’s just the stems and leaves 

I've never had an issue in my discus tank with pothos and I have stems and sometimes leaves in the tank.  I don't think this is a legitimate concern.

[flyingcow]

On 3/11/2024 at 4:35 PM, MattyM said:

Right here, on the good ol' AC site:

https://www.aquariumcoop.com/blogs/aquarium/pothos#:~:text=You often see pothos used,having problems with this plant.

TL;DR - nope, pothos are fine, even the stems and leaves. Many of my new shoots are in the water for weeks before I either trim or pull them above the lid, never had any problems. 

And yes, with pothos I need to fertilize more often, and trim the roots here and there. 

Thank you!

I was already planning on pulling them temporarily in order to simplify my system while solving my bba problem, but I'll look forward to puttin em back in!

 

 

[flyingcow]

Ok now I've started reading. I never realized it was calcium oxalate a.k.a. beer stone! In a brewery, we use an acid rinse step to get rid of it. It forms on the hot side of the brewery. 

[dasaltemelosguy]

On 3/11/2024 at 12:46 PM, flyingcow said:

Is there information on this being toxic to fish? Never heard of this before! Not trying to question you, but I have been having an issue with fish death that I'm 99% sure is parasitic, and a parasitic treatment has stopped the fish death for 6 weeks so far, but now I want to understand this better.

 

@MattyM & @flyingcow, yes, Pothos has that reputation, but many houseplants have that oxalate in the leaves. When we were measuring these types of plants for nitrate uptake, we definitely saw what you were concerned about - some are nutrient hogs and pothos was 2^nd only to lucky bamboo in that regard. Particularly under red light, it was an incredible nitrate hog.

 

The oxalate would be mildly toxic if it were water soluble at a pH fish thrive it, but it requires a very acidic environment to actually leach into the water. The oxalate is therefore in crystal form in the leaves and when animals chew on it, it is an irritant. When it dissolves in a pH below 5, it forms oxalic acid which is not toxic at all so you're safe to use it. 

 

In the article the others mentioned, there's a late addition where I tested the water for the oxalates with urine test strips as that same test will be positive for oxalates to test for kidney stone risk. None dissolved into my tank water at a pH of 7.5.  I literally had to boil the pothos leaves to get any measurable amount of oxalate into the water: 

 

 

Insofar as sucking up all the nutrients for aquatic plants, I can't say but I wouldn't be surprised as it did not mix well with most other houseplants grown emergently. Most that I tried in the beginning died and I assumed, starved out by pothos and lucky bamboo.  But I could be wrong about the latter. I had success with balancing the nutrient uptake with stronger lighting over the other plants so you may be able to balance the uptake with the lighting. 

 

This is the oxalate / pH. As you can see, there's not a lot of aquatic situations that would see the oxalates dissolve.

 

The diamond line is calcium oxalate:

 

 

These tanks are packed full of houseplants. When I first installed them, they tended to uptake more nitrates in the beginning. It dropped an overstocked, 200-gallon, large cichlid tank from 80PPM to 0PPM! This eventually settled out at around 10PPM of nitrates which was still quite a reduction:

 

 

 

 

 

 

 

 

 

 

The plants growing in these tanks are:

 

Pothos

Lucky Bamboo

Lotus Bamboo

Monstera

Peace Lily

Anthurium

Prayer Plant

Bird of Paradise (cuttings)

Earthstars

Cordyline

 

I used common plastic lighting grid from Lowes and cut it to size to support the plants and pass the light.

 

All of these seem to be growing. The Earthstars or bromeliads made no sense, at least not with my limited knowledge of plants. They are epiphytes and literally can get moisture from humidity. I added them for 'temporary' color, assuming they'd die in a week or two, but they've doubled in size in just weeks. So, it was a total surprise to see them THRIVE in aquariums.

 

In fact, their growth was so out of the ordinary, I joined a bromeliad Facebook forum just to ask some experts why it worked!🤣 

 

(they all seemed to think that it was probably the unusually high availability of nitrogen for that plant)

 

VIDEOS OF THESE TANKS:

 

Edited March 12 by dasaltemelosguy
Forgot links to videos.

[Wisdom]

On 3/9/2024 at 5:48 AM, cmo1922 said:

This. Eventually I have to pull the pothos. I have one in my 20 gal I think I'm going to have to pull soon. I use them when I start up tanks to control nutrients, or if I don't plan to keep other plants in the tank. If you find you can't keep your nitrates above 5 ppm and you are fertilizing, I would recommend pulling.

Also, OMG the little house, where did you find that? Not to derail from poster's question, but this is too good!

Thank you! I designed and built the fishing cabin from hobby wood. It covers my ugly hang on back filter. There's better photos here: 

 

 

[flyingcow]

On 3/11/2024 at 10:45 PM, dasaltemelosguy said:

 

@MattyM & @flyingcow, yes, Pothos has that reputation, but many houseplants have that oxalate in the leaves. When we were measuring these types of plants for nitrate uptake, we definitely saw what you were concerned about - some are nutrient hogs and pothos was 2^nd only to lucky bamboo in that regard. Particularly under red light, it was an incredible nitrate hog.

 

The oxalate would be mildly toxic if it were water soluble at a pH fish thrive it, but it requires a very acidic environment to actually leach into the water. The oxalate is therefore in crystal form in the leaves and when animals chew on it, it is an irritant. When it dissolves in a pH below 5, it forms oxalic acid which is not toxic at all so you're safe to use it. 

 

In the article the others mentioned, there's a late addition where I tested the water for the oxalates with urine test strips as that same test will be positive for oxalates to test for kidney stone risk. None dissolved into my tank water at a pH of 7.5.  I literally had to boil the pothos leaves to get any measurable amount of oxalate into the water: 

 

 

Insofar as sucking up all the nutrients for aquatic plants, I can't say but I wouldn't be surprised as it did not mix well with most other houseplants grown emergently. Most that I tried in the beginning died and I assumed, starved out by pothos and lucky bamboo.  But I could be wrong about the latter. I had success with balancing the nutrient uptake with stronger lighting over the other plants so you may be able to balance the uptake with the lighting. 

 

This is the oxalate / pH. As you can see, there's not a lot of aquatic situations that would see the oxalates dissolve.

 

The diamond line is calcium oxalate:

 

 

These tanks are packed full of houseplants. When I first installed them, they tended to uptake more nitrates in the beginning. It dropped an overstocked, 200-gallon, large cichlid tank from 80PPM to 0PPM! This eventually settled out at around 10PPM of nitrates which was still quite a reduction:

 

 

 

 

 

 

 

 

 

 

The plants growing in these tanks are:

 

Pothos

Lucky Bamboo

Lotus Bamboo

Monstera

Peace Lily

Anthurium

Prayer Plant

Bird of Paradise (cuttings)

Earthstars

Cordyline

 

I used common plastic lighting grid from Lowes and cut it to size to support the plants and pass the light.

 

All of these seem to be growing. The Earthstars or bromeliads made no sense, at least not with my limited knowledge of plants. They are epiphytes and literally can get moisture from humidity. I added them for 'temporary' color, assuming they'd die in a week or two, but they've doubled in size in just weeks. So, it was a total surprise to see them THRIVE in aquariums.

 

In fact, their growth was so out of the ordinary, I joined a bromeliad Facebook forum just to ask some experts why it worked!🤣 

 

(they all seemed to think that it was probably the unusually high availability of nitrogen for that plant)

 

VIDEOS OF THESE TANKS:

 

Yeah, I've had pothos in a breeder box for over a year and settled right in around 10 as well. I was on travel for work for 6 months, so that limited my time to take care of the tank and also limited my time to fertilize (hence the BBA). It'll be interesting to see how the tank behaves now that I have it out for a while!

[Tanked]

 

 I have (I hope) reestablished  Hornwort in one tank with Pothos. The Pothos has recently put out a new submerged leaf, but the rest of the vine has suddenly died.  Did Hornwort out compete my Pothos?  The Pothos has been growing in this and another tank for more than two years.  In my case it is not the nutrient hog it was rumored to be, or poisoned any fish. Pothos was placed in the other planted community tank to combat algae.  It is healthy, but doe not outcompete the other plants or the algae.🙁