How much life is possible in a siren tank?

[GA Science Teacher]

I am working to make a 75 gallon native tank for a classroom setup, as naturally as possible, including both sirens and a few representatives of other SE native aquatic life. It's important to the lessons I want to use to have as many of the natural cycles as possible cycling in the tank. I'm opening to using either one lesser or several dwarves, whatever would work best for my objectives. I'd appreciate any and all advice on the following:

1. A heavily planted tank is a must for me, in order to allow natural nutrient cycles to take place. I've seen some people say that plants don't work with lesser sirens because they dig too much, but others seem to use them fine. Are there any guidelines I can use? Any recommendations on plants? I would prefer native plants but am willing to use other options.

2. In order to have a self-sustaining tank, I would prefer to use Walstad method with dirt under the sand. But is that impossible with sirens due to their digging and is sand-only the only reasonable option? Perhaps dirt-under-sand could work with dwarves, but not lessers?

3. With heavily-planted, well-cycled tank with chemical levels carefully monitored, are water changes still necessary or not?

4. Which native fish could potentially work as aquarium-mates with either dwarves or lessers? Which native invertebrates may work? It seems that some people have tried fish successfully before, but if you are absolutely certain it wouldn't work, then I'm open to installing a glass divider halfway through the tank and keeping a lesser or several dwarves on one side and the fish on the other side. The extra advantage there could be more water movement on the fish side and less on the siren side. If I did that, where would it be ideal to keep the divider boundaries? Just down to the substrate, halfway down the substrate, or all the way down to the bottom? All the way to the top of the water, several inches above the top, or could I allow a bit of water at the top to cycle across both tanks?

5. Considering everything I've said above, what would my lid setup look like? I'd need some sort of lighting to maintain the plants, so is it a better idea to find a lid with installed lights to meet my needs, or should I just use a well-fitting screen with separate housed lamps shining above it?

6. What would the best filter option be, all above information considered?


I believe that's all the questions I have. From all the information I've read online, things like temps and feeding seem pretty clear.

 

[JM29]

I'm afraid I don't know enough about sirens to give very relevant answers.
I'll try to do my best :

1- Floating plants like Limnobium laevigatum will do well in your tank. Rootless plants like Ceratophyllum are also interesting. Elodeas grow well, even without being rooted.

2-you can put a layer of clean sand on a layer of Walstad soil to avoir digging problems.

3- water changes are not necessary, except if you notice à cervical problem or if you want to simulate à rainy period.

4- No relevant suggestion for native fish, except That fish will probablement try to eat siren's gills.

5- Sorry, nothing to suggest. Takeshi into accourt escape risks.

6- Normally, Walstad method suppose no filter ...

 

[michael]

I'm afraid I don't know enough about sirens to give very relevant answers.
I'll try to do my best :

1- Floating plants like Limnobium laevigatum will do well in your tank. Rootless plants like Ceratophyllum are also interesting. Elodeas grow well, even without being rooted.

2-you can put a layer of clean sand on a layer of Walstad soil to avoir digging problems.

3- water changes are not necessary, except if you notice à cervical problem or if you want to simulate à rainy period.

4- No relevant suggestion for native fish, except That fish will probablement try to eat siren's gills.

5- Sorry, nothing to suggest. Takeshi into accourt escape risks.

6- Normally, Walstad method suppose no filter ...

I am working to make a 75 gallon native tank for a classroom setup, as naturally as possible, including both sirens and a few representatives of other SE native aquatic life. It's important to the lessons I want to use to have as many of the natural cycles as possible cycling in the tank. I'm opening to using either one lesser or several dwarves, whatever would work best for my objectives. I'd appreciate any and all advice on the following:

1. A heavily planted tank is a must for me, in order to allow natural nutrient cycles to take place. I've seen some people say that plants don't work with lesser sirens because they dig too much, but others seem to use them fine. Are there any guidelines I can use? Any recommendations on plants? I would prefer native plants but am willing to use other options.

2. In order to have a self-sustaining tank, I would prefer to use Walstad method with dirt under the sand. But is that impossible with sirens due to their digging and is sand-only the only reasonable option? Perhaps dirt-under-sand could work with dwarves, but not lessers?

3. With heavily-planted, well-cycled tank with chemical levels carefully monitored, are water changes still necessary or not?

4. Which native fish could potentially work as aquarium-mates with either dwarves or lessers? Which native invertebrates may work? It seems that some people have tried fish successfully before, but if you are absolutely certain it wouldn't work, then I'm open to installing a glass divider halfway through the tank and keeping a lesser or several dwarves on one side and the fish on the other side. The extra advantage there could be more water movement on the fish side and less on the siren side. If I did that, where would it be ideal to keep the divider boundaries? Just down to the substrate, halfway down the substrate, or all the way down to the bottom? All the way to the top of the water, several inches above the top, or could I allow a bit of water at the top to cycle across both tanks?

5. Considering everything I've said above, what would my lid setup look like? I'd need some sort of lighting to maintain the plants, so is it a better idea to find a lid with installed lights to meet my needs, or should I just use a well-fitting screen with separate housed lamps shining above it?

6. What would the best filter option be, all above information considered?


I believe that's all the questions I have. From all the information I've read online, things like temps and feeding seem pretty clear.

The best I can suggest for other tank inhabitants would be freshwater shrimp and small "bugs" that could be siren food. Dwarf sirens have a different set of requirements than lessor or greater sirens. None of the sirens lend them themselves to a community tank.

 

[minorhero]

I am working to make a 75 gallon native tank for a classroom setup, as naturally as possible, including both sirens and a few representatives of other SE native aquatic life. It's important to the lessons I want to use to have as many of the natural cycles as possible cycling in the tank. I'm opening to using either one lesser or several dwarves, whatever would work best for my objectives. I'd appreciate any and all advice on the following:

1. A heavily planted tank is a must for me, in order to allow natural nutrient cycles to take place. I've seen some people say that plants don't work with lesser sirens because they dig too much, but others seem to use them fine. Are there any guidelines I can use? Any recommendations on plants? I would prefer native plants but am willing to use other options.

2. In order to have a self-sustaining tank, I would prefer to use Walstad method with dirt under the sand. But is that impossible with sirens due to their digging and is sand-only the only reasonable option? Perhaps dirt-under-sand could work with dwarves, but not lessers?

3. With heavily-planted, well-cycled tank with chemical levels carefully monitored, are water changes still necessary or not?

4. Which native fish could potentially work as aquarium-mates with either dwarves or lessers? Which native invertebrates may work? It seems that some people have tried fish successfully before, but if you are absolutely certain it wouldn't work, then I'm open to installing a glass divider halfway through the tank and keeping a lesser or several dwarves on one side and the fish on the other side. The extra advantage there could be more water movement on the fish side and less on the siren side. If I did that, where would it be ideal to keep the divider boundaries? Just down to the substrate, halfway down the substrate, or all the way down to the bottom? All the way to the top of the water, several inches above the top, or could I allow a bit of water at the top to cycle across both tanks?

5. Considering everything I've said above, what would my lid setup look like? I'd need some sort of lighting to maintain the plants, so is it a better idea to find a lid with installed lights to meet my needs, or should I just use a well-fitting screen with separate housed lamps shining above it?

6. What would the best filter option be, all above information considered?


I believe that's all the questions I have. From all the information I've read online, things like temps and feeding seem pretty clear.

1) Vallisneria has native options, will grow well low tech, and looks good in a big tank. That would be my main suggestion. Sagittaria Subulata (either dwarf or the full size option) would be another good choice. Either forms big long roots and reproduces relatively quickly. I've never kept sirens, so I can't tell you with certainty that they will work for them, but I've kept plenty of other rooting fish and so long as you let the plants establish first for a couple of months, I haven't had a problem.

2) I don't like dirt tanks, I do not find them appealing, sustainable long term (more then a year) or easier to deal with then non-dirt options. Diana Walstad wrote her book in the 90s when we did not have easy access to cheap fertilizer options. The whole reason for what we now call a Walstad tank (the instructions for which are invented by the internet, and do not exist anywhere in her book) was to save money. And to this day that is the Walstad tank's only advantage. How much money does it save? Today, it's about 20 dollars. Soooo this is a long way of saying, just use sand.

3) So here you are going to get different information. I would say VERY emphatically that YES water changes are necessary. They are always necessary. Why? Well for one thing there is more to keeping a well planted tank then ammonia, nitrite, nitrate, and ph. BUT those are generally the only things we test for. What happens if you have too much magnesium in your tank? We don't have a test kit for that. If you do water changes you don't have to worry about it, but if you don't do water changes, you could easily spend all your time fighting algae blooms or fishing out dead animals. In the wild plants and animals are either in a massive body of water like a lake/pond or they are in a stream with constantly turning over water flowing past them. Either way its a situation we can not replicate in the home aquarium, but the closest we get is by doing regular large water changes.

4) I have not kept sirens before so I can't say whether fish will work or not. I keep several other species of newts with ricefish, male fancy guppies, and celestial pearl danios. I have even (somewhat by accident) kept a rainbow darter in an alpine newt tank while the newts were breeding. The darter is still there with the babies now beginning to morph out (can't catch the darn darter without draining the tank). I won't say the darter didn't eat some of the babies (never saw it but I'm sure it must have happened) but I can say that I have kept a native fish with newts for whatever that's worth.

5) Most people either make their own lid or buy a mesh lid. I make my own. I've done it a few ways but my current favorite way is using pvc trim board and making a lid that fits around the edges. A standard rimmed tank has a little ledge perfect for a lid like this to sit on. Here is a picture of a 20 long with a lid I made:

Home depot sells these pvc trim boards for about 30 dollars for a 2x4 sheet. You would also need some pvc pipe cement to glue it together. Either way you want a lid you can put a fan on or near that blows on the water's surface. This will increase your evaporation but will lower the temperature down up to 6 degrees below ambient. This is by far the cheapest and easiest way to lower water temperature which is important for newts, or sirens in your case.

6) Any filter that is slow moving and can fit around your lid will be fine. Most people use sponge filters because they are cheap, you can poke an air hose through a mesh lid, and they produce minimal flow. I use sponge filters on my tank rack but for my display tanks I use canister filters. If you go the custom lid route you can drill a hole in the appropriate place to stick a lily pipe and have a lid that will keep all animals inside but still allow your filter access. For a canister filter, they usually have too much flow, so I use a ball valve on the return to turn down the flow. Sometimes these are built in, sometimes you need to add one yourself, depends on the filter.

Other things you need to know but didn't ask about.

If you want a lush planted tank you need to fertilize your plants. Siren poop won't do it by itself. Even if you go with a dirt tank, the dirt will be depleted (quickly if you have a lot of plants, as in within 6 months). I use Nilocg Thrive in all my tanks. In the past I've used Aquarium Co-Op Easy Green. I dose per package directions and do big water changes once a week. I've done this with breeding newts, eggs, larva, and morphing juveniles with no negative effects. I do avoid use of any algicides though (this includes 'liquid co2' products).

People are very conservative with what they will put in a newt tank, but I've found zero issues with fertilizers which just replicate what's in the dirt anyway.

Because you need to be doing water changes you should have a good method of doing them quickly. I use a python water change system with a guard over the gravel vac, but some people like using a water pump. Whatever you use, have it in place before you start up the tank so you can do water changes easily.

Good luck!

 

[GA Science Teacher]

6- Normally, Walstad method suppose no filter ...

I've seen people say that online, but Walstad's own book actually recommends a low-flow filter.

 

[GA Science Teacher]

2) I don't like dirt tanks, I do not find them appealing, sustainable long term (more then a year) or easier to deal with then non-dirt options. Diana Walstad wrote her book in the 90s when we did not have easy access to cheap fertilizer options. The whole reason for what we now call a Walstad tank (the instructions for which are invented by the internet, and do not exist anywhere in her book) was to save money. And to this day that is the Walstad tank's only advantage. How much money does it save? Today, it's about 20 dollars. Soooo this is a long way of saying, just use sand.

The appeal for me in using this sort of tank isn't a cost issue, it's the desire to use and demonstrate as many of the natural biological cycles as possible in order to be a teaching tool for my students. Of course, if the cycles aren't working and the tank isn't sustainable that defeats the purpose. So far I've seen a great deal of controversy over how sustainable Walstad tanks are with very strong opinions on both sides.

3) So here you are going to get different information. I would say VERY emphatically that YES water changes are necessary. They are always necessary. Why? Well for one thing there is more to keeping a well planted tank then ammonia, nitrite, nitrate, and ph. BUT those are generally the only things we test for. What happens if you have too much magnesium in your tank? We don't have a test kit for that. If you do water changes you don't have to worry about it, but if you don't do water changes, you could easily spend all your time fighting algae blooms or fishing out dead animals. In the wild plants and animals are either in a massive body of water like a lake/pond or they are in a stream with constantly turning over water flowing past them. Either way its a situation we can not replicate in the home aquarium, but the closest we get is by doing regular large water changes.

Yup, and I understand this as the greatest difficulty in a "small" tank. Like you say, the habitat isn't self-contained in the wild, and regular turnover is part of the water cycle.

If you want a lush planted tank you need to fertilize your plants. Siren poop won't do it by itself. Even if you go with a dirt tank, the dirt will be depleted (quickly if you have a lot of plants, as in within 6 months). I use Nilocg Thrive in all my tanks. In the past I've used Aquarium Co-Op Easy Green. I dose per package directions and do big water changes once a week. I've done this with breeding newts, eggs, larva, and morphing juveniles with no negative effects. I do avoid use of any algicides though (this includes 'liquid co2' products).

People are very conservative with what they will put in a newt tank, but I've found zero issues with fertilizers which just replicate what's in the dirt anyway.

Is the assumption that you're cutting back growth and removing dead plant parts? Because otherwise I don't see why the tank nutrients would deplete so rapidly, as there's no net loss from the tank. Yes, a lot would be used up as the tank fills with growth, but couldn't you reach an equilibrium at some point? Or is a 75 gallon tank just too small to allow any dead leaves to decompose and add back what they initially took?

I wonder, if there were snails in there of a size that were getting eaten by the fish, whether you could find an equilibrium of snails eating back enough growth and pooping it out with the fish keeping their population down.

 

[GA Science Teacher]

And thank you everyone for the plant and co-inhabitant suggestions

 

[minorhero]

The appeal for me in using this sort of tank isn't a cost issue, it's the desire to use and demonstrate as many of the natural biological cycles as possible in order to be a teaching tool for my students. Of course, if the cycles aren't working and the tank isn't sustainable that defeats the purpose. So far I've seen a great deal of controversy over how sustainable Walstad tanks are with very strong opinions on both sides.






Yup, and I understand this as the greatest difficulty in a "small" tank. Like you say, the habitat isn't self-contained in the wild, and regular turnover is part of the water cycle.





Is the assumption that you're cutting back growth and removing dead plant parts? Because otherwise I don't see why the tank nutrients would deplete so rapidly, as there's no net loss from the tank. Yes, a lot would be used up as the tank fills with growth, but couldn't you reach an equilibrium at some point? Or is a 55 gallon tank just too small to allow any dead leaves to decompose and add back what they initially took?

I wonder, if there were snails in there of a size that were getting eaten by the fish, whether you could find an equilibrium of snails eating back enough growth and pooping it out with the fish keeping their population down.

The tank is too small to make a system 'work' and still look 'good'. Is it possible to grow a plant and keep it alive without adding anything? Ya it is. Look up "life in jars" on YouTube. Is it possible to do this and have it look not like a big tank of mud and algae? No, no it is not. We cannot replicate natural cycles in practical tank sizes.

It is possible to have a really nice tank but it requires maintenance. Anyone that tells you otherwise, ask to see their tank.

 

[GA Science Teacher]

The tank is too small to make a system 'work' and still look 'good'. Is it possible to grow a plant and keep it alive without adding anything? Ya it is. Look up "life in jars" on YouTube. Is it possible to do this and have it look not like a big tank of mud and algae? No, no it is not. We cannot replicate natural cycles in practical tank sizes.

It is possible to have a really nice tank but it requires maintenance. Anyone that tells you otherwise, ask to see their tank.

Thank you much. All of this can be part of the teachable process for the students - pointing out what is possible in the tank, what is not possible, how it falls short of a working ecosystem and how those specific shortcomings would be addressed in a natural environment.

 

[eldaldo]

I just want to chime in that I fall into that category of people who are Pro dirted tank. I agree you need to cap with sand and eventually need to add root tabs, but you'd eventually need to do this with aquasoil too. Also stick with a dirt that is more topsoil based than one that is peat based. I've had mixed luck with peat based soil. I have attached a picture of my triturus karelinii dirt substrate tank that has been running for two years and I think it still looks great.

I have cherry shrimp and snails in there and they help with breaking things down. Last fall, a little after a year of it being set up, I added some root tabs and do this every 4-6 months. Once I notice my stem plants seem to be starving. I've noticed the crypts and epiphytes (Java fern, anubias, bucephalandra) do better for longer than my stem plants which grow faster and need more nutrients.

To me, you could set up a tank that relies heavily on those types of plants and see just how long you could go without adding fertilizer. You'd want to keep an eye out for yellowing leaves, black leaves, or holes in the leaves.

Minorhero is right that this system is too small to to go self sustaining without any additional inputs. In truth there are none of these in the wild either, unless you count the planet as a whole, and even then we rely on sunlight to fuel the whole system. Every little stream relies heavily on rain and leaf litter (or other detritus washed in by rain).

But this is perfect for teaching. Add fallen leaves to the tank and watch as microorganisms decompose them (shrimp and snails are good at this too). The nice thing about not having fish in your tank is that sirens probably won't bother eating the coepods and cyclops since they are too small and you can see their populations wax an wane based on how much stuff you are putting in the tank. Sometimes I put veggies in my tank for my nerite snails and everything else seems to love them too.

You will have to remove plants sometimes, especially if they grow so thick they block the light from other plants (floating plants and stem plants usually do this). This is a net loss of nutrients from the system so you'll have to add that back in with some sort of fertilizer like microhero said. I prefer root tabs because they seem to have a longer effect than the daily or weekly micro fertilizer.

I have also noticed that water changes every two weeks really helps my plants. Especially Java fern. You can tell when I've stopped doing water changes because it starts to look ugly. I think it is getting potassium from my tap water and when it runs out it suffers. A 75g is a big tank to do changes on, but if you've got a sink in your room, buy one of those water change kits with the long hose, it is life changing.

Good luck! I'd love to see some pictures!