# Growth Stalling in Walstad Tank



## max_clare (Sep 9, 2019)

Hey guys, this is my first post! So I set up a 5 gallon Walstad tank 6 months ago, and I’ve noticed that the growth of some of my plants has been a bit stalled, so I wanted to ask for some advice. My specs are:

Substrate: Miracle-Gro Organic Potting Mix topped with inert gravel 
Lighting: 13 watt daylight CFL on for 10 hours a day
Filtration: none 
Plants: Anacharis, jungle val, dwarf sag, crypt wendtii, hygro polysperma
Livestock: 2 endlers livebearers, 1 Amano shrimp

So when I first set up the tank, the anacharis was growing crazy fast, almost out of control. However, now the growth has slowed down significantly, it’s not really putting down roots anymore, and some of the pieces have turned brown. I also had hygro polysperma which never really grew well from the beginning, and now it’s almost completely dead.

Meanwhile, my vals and my dwarf sag have been growing, and have now overtaken the anacharis, however the growth has been a bit slower recently with these too, so I want to make sure to investigate the problem before it goes on too long. They’re still putting out runners, but the vals don’t seem to have much vertical growth anymore (maybe because I trimmed them, does that affect their length?) 

Crypts are slow and steady, as crypts tend to be.

So I was thinking the issue could be one of the following,
1. Since my tank has a low bio load, the nitrogen level in the tank is very low, but maybe this could be too low for proper plant fertilization?
3. 10 hours might not be enough light? I originally turned it down several months ago when I saw algae on the dying hygro, but now I have zero algae.
3. Since my nitrogen levels are so low, I’ve been doing pretty infrequent water changes, but maybe the plants aren’t getting enough minerals from fresh tap water. Should I up my water change schedule?

Also let me know any other root causes of the issue that I might not be thinking of. 

I’ll also include some photos of my tank: first is initial setup, second is a few weeks after, with lots of anacharis growth but hygro slowly dying, and the last one is now, where vals have overtaken and anacharis is stalling. 

Please excuse the long post! I’m new here 🙂


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## Streetwise (May 24, 2019)

It looks you are doing great! You could add more fish and shrimp.

Cheers


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## Desert Pupfish (May 6, 2019)

max_clare said:


> So I was thinking the issue could be one of the following,
> 1. Since my tank has a low bio load, the nitrogen level in the tank is very low, but maybe this could be too low for proper plant fertilization?
> 3. 10 hours might not be enough light? I originally turned it down several months ago when I saw algae on the dying hygro, but now I have zero algae.
> 3. Since my nitrogen levels are so low, I’ve been doing pretty infrequent water changes, but maybe the plants aren’t getting enough minerals from fresh tap water. Should I up my water change schedule?


Nice tank! I think you're right on all 3 counts.

This is pretty typical for a soil tank. You get an initial burst of growth, and then as the soil stops leaching nutrients into the water you get less growth from fast growing stem plans. And as the soil gets depleted over time, the root feeders slow down as well. And with your really low bioload of just 2 Endlers & one shrimp, they're not gonna provide much waste to compensate. Unless the Endlers are a breeding pair? Or do you have two males? Like @Streetwise says, sounds like you've got room for some more livestock if you wanted. 

Lighting: increasing your lighting period will increase your plants needs for nutrients, and if that's not met could cause an algae bloom. You could transition over to slow growing root feeders like crypts, & java fern & anubias. Or if you wanna keep the jungle val & anacharis going, fertilize with liquid ferts and/or root tabs. Or add more critters to provide more waste to feed the system. Do you have any snails? They can help aerate your substrate, and their populations will ebb & flow according to the amount of available food (algae, leftover fish food & waste etc)--serving as a barometer of the overall system. If you get a lot of snails, that'd be a great sized tank for a couple of pea puffers. But if you get more fish, you'd probably want to add some filtration, or at least an airstone.

Water changes: not sure of your water parameters, but if you're using dechlorinated tap water the neutralized chloramines could add some nitrogen--worth giving a try to see what happens. 

Regardless, it's looking good. Keep us posted on your progress


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## max_clare (Sep 9, 2019)

Thank you for the response? I was wondering what type of liquid fertilizer you would recommend adding, if I was going that route? There seems to be many available, and I haven’t really looked into them before.


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## minorhero (Mar 28, 2019)

max_clare said:


> Thank you for the response? I was wondering what type of liquid fertilizer you would recommend adding, if I was going that route? There seems to be many available, and I haven’t really looked into them before.


ThriveC for a low tech no co2 tank.


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## united natures (May 15, 2019)

max_clare said:


> Hey guys, this is my first post! So I set up a 5 gallon Walstad tank 6 months ago, and I’ve noticed that the growth of some of my plants has been a bit stalled, so I wanted to ask for some advice. My specs are:
> 
> Substrate: Miracle-Gro Organic Potting Mix topped with inert gravel
> Lighting: 13 watt daylight CFL on for 10 hours a day
> ...


Your tank seems pretty fine to me. I don't see any issues.

The point of Walstad tanks isn't unlimited plant growth, the point is to reach an equilibrium with the environment where you don't have to do any maintenance. 

Seems like your tank has reached that point...

Just a note: with the Walstad method you are basically letting nature take its course. In nature, your Anacharis, jungle va, hygros etc are all competing against one another. They will not grow together as one big happy family. Eventually, one species will win and push out the other species (usually the winner is one of the "weeds" like hygro polysperma).


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## max_clare (Sep 9, 2019)

united natures said:


> Your tank seems pretty fine to me. I don't see any issues.
> 
> The point of Walstad tanks isn't unlimited plant growth, the point is to reach an equilibrium with the environment where you don't have to do any maintenance.
> 
> ...


Thank you for your response! It seems like, in my case, the jungle val has taken over, and the hygro and anacharis are being outcompeted. Interesting!

I'm curious, what set of conditions are required for plants to thrive together, rather than one outcompeting another? And why do conventional tanks fit this criteria, but walstad tanks don't?


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## united natures (May 15, 2019)

max_clare said:


> I'm curious, what set of conditions are required for plants to thrive together, rather than one outcompeting another? And why do conventional tanks fit this criteria, but walstad tanks don't?


In conventional planted tanks you are constantly adding nutrients so that the plants are not starved and competing. You are also constantly pruning the plants so that fast growing weeds do not take over. 

So constant addition of nutrients + pruning allows you to maintain this artificial environment where multiple plant species thrive together

Walstad tanks by definition do not use Co2/fertilizers so that's why they're different


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