Threadfin Rainbowfish – Complete Care Guide

This fish species only grows to about 2 to 2.5 inches in length. They’re great for smaller aquariums which will be discussed later in this guide. This guide will also discuss general Threadfin Rainbowfish care, including their aquarium requirements, dietary needs, and compatible tank mates.

Threadfin Rainbows are one of the smaller species of rainbowfish available in the hobby. As stated above, they grow to about 2.5 inches when grown, making them an excellent option for 10-gallon fish tanks. I’d recommend up to 6 individuals for a 10-gallon aquarium, but I highly suggest setting up a larger fish tank if you want to keep more Threadfins or introduce other fish species.

They’re a great option for well-planted aquariums and will not bother the different species of flora in the fish tank. Threadfin Rainbows, like other rainbowfish, are known to be jumpers. I highly recommend keeping a well-fitted lid on your aquarium to prevent this.

They do best in slightly acidic to neutral water so consider adding some driftwood, peat moss, or Indian Almond Leaves to help acidify the water. They are usually pretty hardy and can tolerate varying water parameters. I recommend keeping their pH between 6.0 and 7.5. The carbonate hardness (KH) in the aquarium should be anywhere between 7 and 10. The aquarium’s water temperature should fall between 72 – 78°F (22.2 – 25.6°C). However, I do recommend keeping the temperature on the higher end of that spectrum.

Because of their small size and even smaller mouths, it’s important to make sure your fish eats the food you are providing. Crushed-up flake food is a great choice for Threadfin Rainbowfish. They should also accept daphnia, baby brine shrimp, and microworms. You don’t want to provide them with food that’s too large because either they won’t consume it or it can get stuck in their mouth. You’re welcome to check out 7 Best Fish Foods For Small Fish if you’re looking for food that your Threadfin should accept without issue.

Threadfin Rainbowfish are very peaceful. They should not bother other fish in the aquarium. This makes them great options for community aquariums with other peaceful fish. They should be easily kept with Tetras, Rasboras, Corydoras, certain Danio species, peaceful Barbs, and many other peaceful fish species. It’s also a great option to build up your school of Threadfin Rainbows. If possible, I recommend keeping a ratio of one male to two females if possible.

I would keep them from fin-nipping fish such as Serpae Tetras, Bettafish, and Tiger Barbs. I would also avoid keeping them with aggressive food eaters because Threadfin Tetras can easily get outcompeted for food.

Breeding Threadfin Rainbows is possible in an aquarium. The hardest part is getting the fry to maturity. It’s a challenge to keep them fed and they develop fairly slowly.

The best way to get started is by adding spawning mops into your aquarium if you want to actively breed your Threadfin Rainbows. You can either purchase them online or make them yourself. They’re available on Amazon if you’re not interested in making them.

The breeding fish will lay the eggs in the floating mop, which you’ll have to check daily for eggs. The eggs can be put into a floating container. As stated earlier the challenge comes after hatching. Making sure they are feeding and getting the right-sized food is key to growing out your fry. Some aquarists recommend feeding Sera Micron or Golden Pearls to Threadfin Rainbow fry.

Threadfins will likely breed with or without a spawning mop. It’s useful to have one to remove eggs. If you allow the eggs to hatch in the fish tank, their success rate will drop significantly due to predation, lack of available food, and many other factors.

Threadfin Rainbowfish may be a fantastic option for your freshwater planted community fish tank. They’re peaceful, have incredible colorations, and have a unique look to them. I highly recommend them if you can get a hold of them and have the patience to deal with their dietary limitations.