Plants not growing in axolotl tank as expected

[DrJade]

Hi,
I have a 55 gallon tank with 3 axolotls and some plants. The plants are not growing and seem to be just staying alive, The tank was set up in September and the bio filter is working very well. Water temp is 62F with a chiller. Never any ammonia or nitrite detected and usually 5-10 ppm nitrate. pH is 8.0. I do 50-70% water changes every 10-14 days, to get rid of debris, brown algae and detritus worms. The tank has diatom algae(brown) that coats all the plants. I wipe it off but to comes back and its hard to not damage the leaves. There is green algae starting up now as well. The axolotls are thriving and love the naturally hard well water. I was hoping the plants would take off more. The floating plants seem bleached out. The other plants are java fern, amazon sword and Anubias and don't look great.. Any input is appreciated. Should I not change as much water and let the nitrates go higher to feed the plants or reduce light so plants do not feed as much. . Or is it the brown algae suffocating the plants? Thanks in advance! Jade

 

[Murk]

Plants! Awesome. Happy to see.

So, two problems I spot, both difficult to solve:

First, lighting. Some of these plants require a lot of light.
The floating plants in nature get full, direct sunlight the entire day (which is a lot of light).
Pale plants is almost always due to too little light; brown diatoms is also a good indicator of dim light (though it can also indicate some other kind of disbalance - diatoms are common in new tanks, but they should have disappeared on their own by now).
What kind of lighting do you have? How long is it on each day?

More complex is that "more light" is not really a good solution here, because you don't have a lot of plants in the aquarium. If you would give the full aquarium more light, you would have many spots without plants but full lighting - so algae would grow.
Now, there is nothing wrong with algae. Just like any other plant, they remove nitrates, make oxygen, stabilise pH... green algae are actually pretty beneficial. They just look very, very unpleasant. Most of us don't want algae-swamped aquariums.

Depending on what kind of light you have, you could try for example to use more light (or longer light), but only on part of the aquarium. Then put all the plants directly under the light.
Would hinder algae growth in the other parts of the aquarium, give the axolotls some nice shade, but also give the plants more light.

Second is temperature. 62F is pretty cool water. That's good, because axolotls like it - but it's too cold for most tropical plants. Anubias, java fern and Amazon sword might survive it (because they're very hardy plants), but they won't thrive. If all other conditions are perfect they might grow very slowly, but it won't be much.
My own tank is usually room temperature (so 66-68F) - actually a bit too warm for axolotls, but still on the cold side for tropical plants. My anubias and java fern do... acceptably, but their growth is still very slow.

So for solutions... well, either you would have to warm the tank (which is bad for the axolotls!) or you might be better of with cold water plants.
As I said, the tropical plants will probably survive, so there's no need to get rid of them - but they won't turn the tank into a lush jungle. If you'd like a really green, growing, thriving tank, you'll probably need plants that like the temperature.


But please do let us know what kind of lighting you have (and how long each day).

 

[DrJade]

Plants! Awesome. Happy to see.

So, two problems I spot, both difficult to solve:

First, lighting. Some of these plants require a lot of light.
The floating plants in nature get full, direct sunlight the entire day (which is a lot of light).
Pale plants is almost always due to too little light; brown diatoms is also a good indicator of dim light (though it can also indicate some other kind of disbalance - diatoms are common in new tanks, but they should have disappeared on their own by now).
What kind of lighting do you have? How long is it on each day?

More complex is that "more light" is not really a good solution here, because you don't have a lot of plants in the aquarium. If you would give the full aquarium more light, you would have many spots without plants but full lighting - so algae would grow.
Now, there is nothing wrong with algae. Just like any other plant, they remove nitrates, make oxygen, stabilise pH... green algae are actually pretty beneficial. They just look very, very unpleasant. Most of us don't want algae-swamped aquariums.

Depending on what kind of light you have, you could try for example to use more light (or longer light), but only on part of the aquarium. Then put all the plants directly under the light.
Would hinder algae growth in the other parts of the aquarium, give the axolotls some nice shade, but also give the plants more light.

Second is temperature. 62F is pretty cool water. That's good, because axolotls like it - but it's too cold for most tropical plants. Anubias, java fern and Amazon sword might survive it (because they're very hardy plants), but they won't thrive. If all other conditions are perfect they might grow very slowly, but it won't be much.
My own tank is usually room temperature (so 66-68F) - actually a bit too warm for axolotls, but still on the cold side for tropical plants. My anubias and java fern do... acceptably, but their growth is still very slow.

So for solutions... well, either you would have to warm the tank (which is bad for the axolotls!) or you might be better of with cold water plants.
As I said, the tropical plants will probably survive, so there's no need to get rid of them - but they won't turn the tank into a lush jungle. If you'd like a really green, growing, thriving tank, you'll probably need plants that like the temperature.


But please do let us know what kind of lighting you have (and how long each day).

Thanks for reply. I have an LED Hygger 957 72 Watt . See specs in picture. Its on full spectrum "daylight setting" 12 hours per day at full brightness. I was going to turn it down but axolotls don't seem bothered. And Blue light at night. The axolotls health is the most important so I do not want to raise the temp. The floating plants are mostly right under the light, so that's why I assumed that are light bleached, as I have had this happen to greenhouse plants with too much light and not enough Nitrogen (we have a commercial greenhouse). The temperature seems a likely culprit for the tropical plants. I do think the diatoms are improving as the green algae moves in, but It is a long time to have it. We have very hard water with lots of silica so the diatoms probably love that. Maybe I need different types of plants? I would love some recommendations for plants that thrive at 60F. Thanks Murk!

 

[MnGuy]

I'm not much help here, but when I read that you changed 50-70 percent of the water at a time I did wonder if that was removing too many nutrients for the plants, especially since your rooted plants are in pots and not in a full substrate that would retain some nutrients.

I keep dwarf water lettuce, frogbit, duckweed, parrot's feather, anubias, bolbitis, bucephalandra and subwassertang in my newt tank that is about 62 degrees Fahrenheit and everything is doing great, so I'm not sure that water temperature is your issue.

I use a cheap Fluval LED from Petco. My surface plants are always exploding. My submerged plants are healthy but grow slowly due to the large amount of surface plants.

My best guess is you don't have enough nutrients and the high silica content in your water supply is causing too many diatoms, which are overwhelming your submerged plants. I don't know that you can do anything about the diatoms if you can't change your water supply.

Good luck.

 

[DrJade]

I'm not much help here, but when I read that you changed 50-70 percent of the water at a time I did wonder if that was removing too many nutrients for the plants, especially since your rooted plants are in pots and not in a full substrate that would retain some nutrients.

I keep dwarf water lettuce, frogbit, duckweed, parrot's feather, anubias, bolbitis, bucephalandra and subwassertang in my newt tank that is about 62 degrees Fahrenheit and everything is doing great, so I'm not sure that water temperature is your issue.

I use a cheap Fluval LED from Petco. My surface plants are always exploding. My submerged plants are healthy but grow slowly due to the large amount of surface plants.

My best guess is you don't have enough nutrients and the high silica content in your water supply is causing too many diatoms, which are overwhelming your submerged plants. I don't know that you can do anything about the diatoms if you can't change your water supply.

Good luck.

That was one of my thoughts as well, that there is not enough Nitrogen. When I do water changes I like to get out most of the debris which seems to take at least a 50% change to do. Also I scrape the diatoms and algae before suctioning and want to remove as many as possible that are floating in the water. The axolotls like the hard water and using filtered would be possible but a huge hassle.

 

[Murk]

Oh, yeah, that's more light than I was expecting. Lighting shouldn't be a problem, then.

I would be surprised if it's a lack of nitrates, because... well, you still have nitrates. If it's usually between 5-10ppm, that means there's still plenty of nitrates to be used.
It could be the fluctuation in nitrates (i.e., you remove most of them in a big water change, and only afterwards do they slowly build up again). But if you have 10ppm nitrates and do a 50% change, you still have 5ppm nitrates. If the nitrates were truly the limiting factor (so your plants are starving for nitrates), those 5ppm would go down to 0 very quickly.

I'll gladly agree the high levels of silica cause the diatoms, but if your plants (or even green algae) are doing well they would outcompete diatoms pretty quickly. The diatoms can't be the only problem.

Will have to think about it some more.

 

[DrJade]

Oh, yeah, that's more light than I was expecting. Lighting shouldn't be a problem, then.

I would be surprised if it's a lack of nitrates, because... well, you still have nitrates. If it's usually between 5-10ppm, that means there's still plenty of nitrates to be used.
It could be the fluctuation in nitrates (i.e., you remove most of them in a big water change, and only afterwards do they slowly build up again). But if you have 10ppm nitrates and do a 50% change, you still have 5ppm nitrates. If the nitrates were truly the limiting factor (so your plants are starving for nitrates), those 5ppm would go down to 0 very quickly.

I'll gladly agree the high levels of silica cause the diatoms, but if your plants (or even green algae) are doing well they would outcompete diatoms pretty quickly. The diatoms can't be the only problem.

Will have to think about it some more.

 

[minorhero]

I'm not great at spotting plant deficiencies. Typically bleached leaves means your nutrients are off. Probably potassium given what I'm seeing but again, I'm not great at identifying these problems. My first thought is what nutrients are you putting in the tank? My guess is nothing coupled with frequent water changes and thars your problem. I see some folks using aquatic plant fertilizers like Easy Green with axolotls without issue and others say not to add anything. If it were my tank I would research the question of ferts a bit more and make a decision on whether you want to try something or not.

The other possibility is that your water is too hard for some / all of the plants you are using. You mentioned you have hard water, what is your TDS out of the tap?

 

[DrJade]

I'm not great at spotting plant deficiencies. Typically bleached leaves means your nutrients are off. Probably potassium given what I'm seeing but again, I'm not great at identifying these problems. My first thought is what nutrients are you putting in the tank? My guess is nothing coupled with frequent water changes and thars your problem. I see some folks using aquatic plant fertilizers like Easy Green with axolotls without issue and others say not to add anything. If it were my tank I would research the question of ferts a bit more and make a decision on whether you want to try something or not.

The other possibility is that your water is too hard for some / all of the plants you are using. You mentioned you have hard water, what is your TDS out of the tap?

143 PPM (8 drops) Not looking to add nutrients. If anything I would change less water as 3 animals should make plenty of Nitrogen.

 

[minorhero]

143 PPM (8 drops) Not looking to add nutrients. If anything I would change less water as 3 animals should make plenty of Nitrogen.

143 TDS is not very hard.

Anyway plants need a lot more then nitrogen to live. That said, if they are not growing well for you and you don't want to change what nutrients they are receiving I suggest trying different plants. Hornwort and pearl weed are two plants that are practically nuisance plants in an aquarium. Another option is subwassertang which tends to grow well in a variety of conditions.