"Natural" tanks - no filter

There is no harm in trying it. Set it up and let it run for several months and decide what you think. It is not much of a commitment, and if you decide it is not for you, then you have another experience under your belt. Put the fish back in your other tank and go back to basics. You might be surprised at how clear the water is.

It is always good to have an extra smallish tank around anyway for a hospital tank or quarantine tank, so you've not wasted anything.

When I set up my 150 (I am now thinking I'm going to dig out my pressurized CO2 equipment for this tank, *sigh* need more power strips) I was sure the meter reader was going to wonder if I had some sort of illegal hydroponic plant growing operation, since I am sure the little dial is spinning faster these days.

 

Hmm. I don't know how to quantify it, but I'd say that at least 60% of the tank is taken up with plants. Does that make sense?

I could not tell you about a pond, I'd just jam it up with plants of varying heights and growth habits, leaving some room for fish, and be sure no floating plants blocked light to the other aquatic plants.

 

Right - put plants all around the sides and across the back without gaps, low plants in front, etc. Then be conservative stocking it. You DO need fish in there, but not as many as you might put in the tank if there was less room taken up by plants.

You can see how packed with plants the 5gal in my pic is, but that might be a bit too much. The bowl filled in more after that pic was taken, with the aquatic clover filling in the bottom, but you would not want more than one fish in that size container - it is just too small for any fish, though a betta would probably be content. I dosed a few drops of Flourish in the bowl as well as in the 5 gal just stir it in with your hand or a spoon or something. Even with a decent fish load plants do much better with ferts. I used Fluorite substrate in both.

 

What kind of lighting do you plan on? This will make a difference. For a 2.5 gallon you'll need to stick with small plants (look in my gallery at the natural bowl - that is 2 gallons) like java moss, Anubias nana "petite" and Cryptocorine species "crypts". These are all low light plants but will not overwhelm a small tank like this as they grow. Let me know what is available to you plant-wise and I can advise you.

Also, do not get a friend for your betta. In a tank like this, "there can be only one," so to speak, and even if you managed to have a mated pair, that is not enough water for more than one fish. Alternatively, you could have a dwarf frog, or several shrimps and several snails, but not more than one fish.

I'd do a very small daily water change on a tank that size, just like a cup of water every day.

Give things a try and let me know how it goes!

 

Ramshorn snails won't get so big, also nerite snails if you can find them. Substrate would ideally be a plant substrate like Fluorite or Eco-Complete, but it is not absolutely required.

There are many plants at the LFS that would not work in a small tank like this, so choose carefully. The plants I list above would be fine.

There is something available called a "palm" light, I think, that is meant to clamp onto a betta bowl or something, and it has a wee tiny compact fluorescent bulb, or just a desk lamp with a pigtail fluorescent bulb (6500 K spectrum) in it would work fine.

 

I'd start out with the shrimp alone and let him cycle the tank for his bioload before adding anything else. Give it a month.

When I say "crypts" I mean Cryptocorine genus, of which the most common will be C. wendtii. Try to get baby plants if you can. People in the hobby call them "crypts" for short.

 

You can run a cycle with plants, but plants won't "cycle" the tank (I am not sure if that was your question). The plants will not mind the cycle. You'll be cycling the tank with the shrimp. Do frequent water changes and keep ammonia and nitrite levels low in the typical manner.