choosing the right nano tank for a betta

[kaleek]

Back into fish keeping after a few years off.
I'm on the hunt for a small tank for my study - 20L max. Planning on a planted setup with shrimp and a betta.
Went to Pets at Home today, spotted the Interpet Edge Glow, 18L, but they were out of stock and it's not on their site either. Liked that one as the filter, heater, etc., were hidden from view.
Struggling to find an alternative - all the others at Pets at Home were either too small or had bad reviews.
Would really appreciate some help here. I'm aware of the cycle process and all that, having kept fish before, and I've got access to media from an established tank.

[coltin]

I'd suggest considering a slightly larger tank, maybe around 40 litres, it would give you more flexibility if you wanted to introduce other inhabitants or if something happened to the betta.

When looking at tanks, keep in mind that the stated litres is usually the full capacity, but in reality, with gravel, decorations and the water level being an inch or so below the top, they tend to hold a bit less than that.

[sSjey]

The filter's likely included in the volume, reducing the actual space for your fish. You can see the specs for the Interpet Edge Glow here, which might give you a better idea: http://www.interpet.co.uk/Media/Interpe ... 1542_7.pdf

[avalyn]

I'd like to add that in the US, standard tank sizes are often based on the outside dimensions, which is pretty irrelevant to the fish. The inside dimensions are what matter, and that's what we should be focusing on.

For low-activity fish like bettas, a good rule of thumb is to provide at least 5 to 6 times their body length in tank space. However, that's for single-fish tanks. If you're planning to keep tankmates, you'll likely need a bigger tank to accommodate them comfortably.

[florist]

What's the tank size in gallons, and what kind of betta are you thinking of? If you want a community tank with betas, I'd say you need at least a 10-gallon tank. Honestly, 20 gallons is way better for a community setup. You could consider adding some peaceful, schooling fish like ember tetras, chili rasboras, or cardinal tetras.

[sSjey]

The 18 litres you mentioned is equivalent to 4.8 gallons, however, it's worth noting that this volume includes the tank's glass thickness, the airspace above the water, and the filter compartment, so the actual water volume is likely to be significantly less than 4.8 gallons.