[-Sutekh]

Hello all,

Wasn't sure where this post should go in terms of categories because it kind of fits in multiple categories.

I have a few tanks, but they are all in rooms or angled away from my office setup while working from home. So I wanted to do something small for the desktop and decided to try to build a 2.5 gallon walstead bowl with some shrimp.

I plan to pull some stems and root growers from one of the tank to get it started. Something like various Ludwigia reopens/super reds/mini... some rotella, and maybe some dwarf sage. Then suspend some pothos, and let the roots grow in. Also thought about throwing in some root floaters too. It will face a south window, but will get indirect sunlight most of the day except in the mornings. The idea is no heater and no filter (plants and substrate will do the converting to Nitrate), and just light it with some sort of LED light. Instead of dirt, I have left over BDBS and plan to drop a root tab or two in there on occasion, and very rarely a splash of a liquid fert, but I'm trying to stay away from liquid for this build as much as possible.

I have a few questions, and probably many many more, but I'm not even sure where to start....

• I suspect it is set up like a traditional planted tank, but just a bit more challenging to balance? The trick is right lighting and low bioload, right?
• What stocking would be appropriate in terms of shrimp/Snails (once cycled of course)
• What lighting would be appropriate for a build like this (looking for LED)? How long do people keep it on for?
• Any problems with root tabs messing up a walstead tank? I can't imagine so, but wanted to ask anyways.
• Anything else I should know?
  
  Thank you!!!

 

[minorhero]

• I suspect it is set up like a traditional planted tank, but just a bit more challenging to balance? The trick is right lighting and low bioload, right?
• What stocking would be appropriate in terms of shrimp/Snails (once cycled of course)
• What lighting would be appropriate for a build like this (looking for LED)? How long do people keep it on for?
• Any problems with root tabs messing up a walstead tank? I can't imagine so, but wanted to ask anyways.
• Anything else I should know?

1) the trick for walstad tanks is the same balance issues as any tank but the nutrient release of dirt is completely unknown. Generally dirt will have SIGNIFICANTLY more nutrients then anything we put in our tanks and thus balance can get out of hand really quickly. Having done a few dirt tanks I now will never go back. Especially something this small just buy a bag of aquasoil and use that as if it were dirt. (ie put down 1 inch and then cap it with an inch or 2 of sand).

2) 2 or 3 snails and 6-10 neocaridina shrimp. They both will breed in there and you can pull out extras when you think its overcrowding.

3) A regular A19 LED lightbulb in the 5000-7000k range just like you would use in your lamps or ceilings. Spend an extra dollar and buy one listed as 'high cri'. Put it in a desk lamp. You mention that this is near a window and the way you wrote your response indicated it might get direct sun? If so make sure it doesn't get direct sun. Block the back of it off, put up a curtain, move it, whatever. Direct sun is something crazy like 1500-2000 par. This tank should be in the 25 par or less range. Depending on how much indirect light from the window it gets, you may need to block off that light anyway. I had a Walstad bowl in the window and it get about 20 par just from the indirect light.

4) You can add root tabs or liquid ferts as you see fit, it won't mess anything up.

5) You will need to do regular water changes as if this were any aquasoil type tank (especally if you use dirt), meaning every day 50% for the first week, every other day for the 2nd week, every three days in week3, and twice in week 4. Thereafter how often you do a water change depends on the bioload, any food you put in, and what fertilizer system you use.

- You will also want to fill this thing with plants. They are your filter so you need a bunch. Hopefully this is helpful.

 

[-Sutekh]

1) the trick for walstad tanks is the same balance issues as any tank but the nutrient release of dirt is completely unknown. Generally dirt will have SIGNIFICANTLY more nutrients then anything we put in our tanks and thus balance can get out of hand really quickly. Having done a few dirt tanks I now will never go back. Especially something this small just buy a bag of aquasoil and use that as if it were dirt. (ie put down 1 inch and then cap it with an inch or 2 of sand).

2) 2 or 3 snails and 6-10 neocaridina shrimp. They both will breed in there and you can pull out extras when you think its overcrowding.

3) A regular A19 LED lightbulb in the 5000-7000k range just like you would use in your lamps or ceilings. Spend an extra dollar and buy one listed as 'high cri'. Put it in a desk lamp. You mention that this is near a window and the way you wrote your response indicated it might get direct sun? If so make sure it doesn't get direct sun. Block the back of it off, put up a curtain, move it, whatever. Direct sun is something crazy like 1500-2000 par. This tank should be in the 25 par or less range. Depending on how much indirect light from the window it gets, you may need to block off that light anyway. I had a Walstad bowl in the window and it get about 20 par just from the indirect light.

4) You can add root tabs or liquid ferts as you see fit, it won't mess anything up.

5) You will need to do regular water changes as if this were any aquasoil type tank (especally if you use dirt), meaning every day 50% for the first week, every other day for the 2nd week, every three days in week3, and twice in week 4. Thereafter how often you do a water change depends on the bioload, any food you put in, and what fertilizer system you use.

- You will also want to fill this thing with plants. They are your filter so you need a bunch. Hopefully this is helpful.

Thanks for the reply! This is very helpful already!

1) Good to know. I was shying away from dirt just because I've never found it required, seems to be a mess, and I learned later on in my time that any inert substrate with proper fertilization seems to grow plants just as well, and is wildly less expensive. Based on my experience with a plain blasting sand and proper nutrients, algae seems to be a non-issue and plants seem to thrive. I have blasting sand in all of my tanks now instead of other substrates. Like the look, easy to plant in, and doesn't make a mess. Sounds like between this answer and your response to #4, I should be good to go with my normal blasting sand/root tab combo.

2) Perfect! This is helpful! That was much more than I actually anticipated to see!

3)Also great info. It would get direct light for a short period of time in the morning, but the location of the bowl can be moved out of indirect light. I assumed direct light would help somehow. Didn't think about the PAR values being so high! Learned something new here. I wasn't sure if a A19 would be strong enough to grow a bowl well. Sounds like it is paired with a desk lamp, and keep it away from the tank a bit, I should be good to go. It's interesting to learn such a low par is required. I'm so used to medium/high light tanks I've basically forgotten you can likely grow the same plants at 20 par...

5) Thanks for the suggestion! Hopefully with an inert substrate, I can get it balanced pretty well. My goal was to do topoffs more than water changes primarily based on a weekly nitrate test of course. I've heard people going weeks to months between water changes, but I suppose that's how delicately I have everything balanced.

Good suggestion with filling with plants. I tend to like a very overgrown look in most of my tanks, so I'm planning on way overplanting it.

Thanks for the awesome suggestions! I truly appreciate it!

 

[-Sutekh]

Ok few updated questions.

So I guess the bowl wouldn't truly be a walstad bowl if I'm using an inert substrate.

Anyone have success with an inert substrate with tabs and found it works well without a filter?

Additionally, what depth substrate range would do ok for a tank without a filter?

I've heard deep to get more surface area. And I've heard shallow.

Also, some of my plant choices are decently quick growers which I figured would work well for bioload management... and might be better than slower growers.

Am I just building a nanotank without a filter at this point?

This has turned into quite the experiment.